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42 hoursserial: 8250_dw: dispatch SysRq character in dw8250_handle_irq()Jacques Nilo1-1/+1
commit 2e211723953f7740e54b53f3d3a0d5e351a5e223 upstream. dw8250_handle_irq() calls serial8250_handle_irq_locked() with the port lock held via guard(uart_port_lock_irqsave). The guard destructor is plain uart_port_unlock_irqrestore(), so a SysRq character captured into port->sysrq_ch by uart_prepare_sysrq_char() is dropped without ever being dispatched to handle_sysrq(). This is the same regression pattern as in serial8250_handle_irq(), introduced when 883c5a2bc934 ("serial: 8250_dw: Rework dw8250_handle_irq() locking and IIR handling") moved the function to the guard()-based locking scheme without using the sysrq-aware unlock helper. Switch to guard(uart_port_lock_check_sysrq_irqsave) so that captured sysrq_ch is dispatched on scope exit, matching the fix in serial8250_handle_irq(). Fixes: 883c5a2bc934 ("serial: 8250_dw: Rework dw8250_handle_irq() locking and IIR handling") Cc: stable@vger.kernel.org Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Signed-off-by: Jacques Nilo <jnilo@free.fr> Link: https://patch.msgid.link/ed56fcaf4af24e4ed011a7bce206e0182acb761c.1778675349.git.jnilo@free.fr Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
42 hoursserial: 8250: dispatch SysRq character in serial8250_handle_irq()Jacques Nilo1-2/+5
commit 71f42b2149a1307a97165b409493665579462ea0 upstream. serial8250_handle_irq() captures a SysRq character into port->sysrq_ch inside serial8250_handle_irq_locked() via uart_prepare_sysrq_char() (reached from serial8250_read_char()). Dispatch of that captured character to handle_sysrq() is expected to happen at port-unlock time, through uart_unlock_and_check_sysrq[_irqrestore](). After commit 8324a54f604d ("serial: 8250: Add serial8250_handle_irq_locked()") the function was reduced to a wrapper that takes the port lock via guard(uart_port_lock_irqsave) whose destructor is plain uart_port_unlock_irqrestore(). The sysrq-aware unlock helper is no longer called, so port->sysrq_ch is captured but never dispatched: BREAK + SysRq key is consumed silently. This was the very condition Johan Hovold's 853a9ae29e978 ("serial: 8250: fix handle_irq locking", 2021) introduced uart_unlock_and_check_sysrq_irqrestore() to address. Switch to the new guard(uart_port_lock_check_sysrq_irqsave), whose destructor is the sysrq-aware unlock helper, restoring the pre-split behaviour. Update the Context: comment on serial8250_handle_irq_locked() so future HW-specific 8250 wrappers know to use the same guard or the explicit sysrq-aware unlock. Verified on RTL8196E with CONFIG_MAGIC_SYSRQ_SERIAL=y: BREAK + 'h' on the console UART produces the SysRq help dump in dmesg and the brk counter in /proc/tty/driver/serial increments correctly. Fixes: 8324a54f604d ("serial: 8250: Add serial8250_handle_irq_locked()") Cc: stable@vger.kernel.org Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Signed-off-by: Jacques Nilo <jnilo@free.fr> Link: https://patch.msgid.link/52692ae6c3501f7940347cef364ad7fcacaab7e5.1778675349.git.jnilo@free.fr Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
42 hoursserial: zs: Convert to use a platform deviceMaciej W. Rozycki2-121/+72
commit 7cac59d08a73cb866ec51a483a6f3fe0f531947c upstream. Prevent a crash from happening as the first serial port is initialised: Console: switching to mono frame buffer device 160x64 fb0: PMAG-AA frame buffer device at tc0 DECstation Z85C30 serial driver version 0.10 CPU 0 Unable to handle kernel paging request at virtual address 0000002c, epc == 803ab00c, ra == 803aafe0 Oops[#1]: CPU: 0 PID: 1 Comm: swapper Not tainted 6.4.0-rc3-00031-g84a9582fd203-dirty #57 $ 0 : 00000000 10012c00 803aaeb0 00000000 $ 4 : 80e12f60 80e12f50 80e12f58 81000030 $ 8 : 00000000 805ff37c 00000000 33433538 $12 : 65732030 00000006 80c2915d 6c616972 $16 : 80e12f00 807b7630 00000000 00000000 $20 : 00000004 00000348 000001a0 807623b8 $24 : 00000018 00000000 $28 : 80c24000 80c25d60 8078b148 803aafe0 Hi : 00000000 Lo : 00000000 epc : 803ab00c serial_base_ctrl_add+0x78/0xf4 ra : 803aafe0 serial_base_ctrl_add+0x4c/0xf4 Status: 10012c03 KERNEL EXL IE Cause : 00000008 (ExcCode 02) BadVA : 0000002c PrId : 00000440 (R4400SC) Modules linked in: Process swapper (pid: 1, threadinfo=(ptrval), task=(ptrval), tls=00000000) Stack : 80760000 00000cc0 00400044 00400040 803aa02c 80d61ab8 00000000 807b7630 80760000 807623b8 807b7628 803aa644 80386998 00000000 80e17780 80220f68 80e17780 80d61ab8 80c17d80 80e17780 80e17780 8063c798 80e17780 80383fa0 00000010 80e17780 00000000 80386998 807a0000 00000000 00400040 8038f848 807623b8 80d61ab8 00000004 80e17780 00000000 803a68e4 80c25e2c 803bb884 ... Call Trace: [<803ab00c>] serial_base_ctrl_add+0x78/0xf4 [<803aa644>] serial_core_register_port+0x174/0x69c [<8077e9ac>] zs_init+0xc8/0xfc [<800404d4>] do_one_initcall+0x40/0x2ac [<8076cecc>] kernel_init_freeable+0x1e4/0x270 [<80605bec>] kernel_init+0x20/0x108 [<800431e8>] ret_from_kernel_thread+0x14/0x1c Code: 2442aeb0 ae120024 ae0200d0 <8c67002c> 50e00001 8c670000 3c06806e 3c05806e afb30010 ---[ end trace 0000000000000000 ]--- (report at the offending commit) -- where a pointer is dereferenced that has been derived from a null pointer to the port's parent device. Since no device is available with legacy probing and it's not anymore a preferable way to discover devices anyway, switch the driver to using a platform device and use it as the port's parent device. Update resource handling accordingly and only request the actual span of addresses used within the slot, which will have had its resource already requested by generic platform device code. Use platform_driver_probe() not just because SCC devices are fixed with solder on board and not straightforward to remove, but foremost because the associated TTY's major device number is the same as used by the dz driver and the first driver to claim it will prevent the other one from using it. Either one DZ device or some SCC devices will be present in a given system but never both at a time, and therefore we want the major device number to be claimed by the first driver to actually successfully bind to its device and platform_driver_probe() is a way to fulfil that. An unfortunate consequence of the switch to a platform device is we now hand the console over from the bootconsole much later in the bootstrap. The firmware console handler appears good enough though to work so late and in particular with interrupts enabled. Since there is one way only remaining to reach zs_reset() now, remove the port initialisation marker as no longer needed and go through the channel reset unconditionally. Fixes: 84a9582fd203 ("serial: core: Start managing serial controllers to enable runtime PM") Signed-off-by: Maciej W. Rozycki <macro@orcam.me.uk> Cc: stable@vger.kernel.org # needs to use .remove_new for <= 6.10 Link: https://patch.msgid.link/alpine.DEB.2.21.2605062328480.46195@angie.orcam.me.uk Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
42 hoursserial: zs: Switch to using channel resetMaciej W. Rozycki2-4/+5
commit 8572955630f30948837088aa98bcbe0532d1ceac upstream. Switch the driver to using the channel reset rather than hardware reset, simplifying handling by removing an interference between channels that causes the other channel to become uninitialised afterwards. There is little difference between the two kinds of reset in terms of register settings that result, and we initialise the whole register set right away anyway. However this prevents a hang from happening should the console output handler in the firmware try to access the other port whose transmitter has been disabled and line parameters messed up. For example this will happen if the keyboard port (port A) is chosen for the system console, unusually but not insanely for a headless system, as the port is wired to a standard DA-15 connector and an adapter can be easily made. Or with the next change in place this would happen for the regular console port (port B), since the keyboard port (port A) will be initialised first. Just remove the unnecessary complication then, a channel reset is good enough. We still need the initialisation marker, now per channel rather than per SCC, as for the console port zs_reset() will be called twice: once early on via zs_serial_console_init() for the console setup only, and then again via zs_config_port() as the port is associated with a TTY device. Fixes: 8b4a40809e53 ("zs: move to the serial subsystem") Signed-off-by: Maciej W. Rozycki <macro@orcam.me.uk> Cc: stable@vger.kernel.org # v2.6.23+ Link: https://patch.msgid.link/alpine.DEB.2.21.2605062323430.46195@angie.orcam.me.uk Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
42 hoursserial: zs: Fix bootconsole handover lockupMaciej W. Rozycki1-21/+8
commit 6c05cf72e13314ce9b770b5951695dc5a2152920 upstream. Calling zs_reset() in the course of setting up the serial device causes line parameters to be reset and the transmitter disabled. We've been lucky in that no message is usually produced to the kernel log between this call and the later call to uart_set_options() in the course of console setup done by zs_serial_console_init(), or the system would hang as the console output handler in the firmware tried to access a port the transmitter of which has been disabled and line parameters messed up. This will change with the next change to the driver, so fix zs_reset() such that line parameters are set for 9600n8 console operation as with the system firmware and the transmitter re-enabled after reset. This also means zs_pm() serves no purpose anymore, so drop it. Fixes: 8b4a40809e53 ("zs: move to the serial subsystem") Signed-off-by: Maciej W. Rozycki <macro@orcam.me.uk> Cc: stable@vger.kernel.org # v2.6.23+ Link: https://patch.msgid.link/alpine.DEB.2.21.2605062308040.46195@angie.orcam.me.uk Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
42 hoursserial: dz: Convert to use a platform deviceMaciej W. Rozycki1-60/+56
commit 5d7a49d60b8fda66da60e240fd7315232fa1754f upstream. Prevent a crash from happening as the first serial port is initialised: Console: switching to colour frame buffer device 160x64 tgafb: SFB+ detected, rev=0x02 fb0: Digital ZLX-E1 frame buffer device at 0x1e000000 DECstation DZ serial driver version 1.04 CPU 0 Unable to handle kernel paging request at virtual address 000000bc, epc == 8048b3a4, ra == 80470a78 Oops[#1]: CPU: 0 UID: 0 PID: 1 Comm: swapper/0 Not tainted 6.19.0-dirty #35 NONE $ 0 : 00000000 1000ac00 00000004 804707ac $ 4 : 00000000 80e20850 80e20858 81000030 $ 8 : 00000000 8072c81c 00000008 fefefeff $12 : 6c616972 00000006 80c5917f 69726420 $16 : 80e20800 00000000 808f8968 80e20800 $20 : 00000000 807f5a90 808b0094 808d3bc8 $24 : 00000018 80479030 $28 : 80c2e000 80c2fd70 00000069 80470a78 Hi : 00000004 Lo : 00000000 epc : 8048b3a4 __dev_fwnode+0x0/0xc ra : 80470a78 serial_base_ctrl_add+0xa0/0x168 Status: 1000ac04 IEp Cause : 30000008 (ExcCode 02) BadVA : 000000bc PrId : 00000220 (R3000) Modules linked in: Process swapper/0 (pid: 1, threadinfo=(ptrval), task=(ptrval), tls=00000000) Stack : 00400044 00400040 8046f4cc 00000000 808a6148 808a0000 808f8968 8086983c 808e0000 8046fc84 1000ac01 00000028 80e20700 802ba3f8 80e20700 80d34a94 80c1b900 80e20700 80e20700 80e20700 80e20700 80444650 00000000 00000000 00000000 807f5a90 808b0094 80447080 00400040 808e0000 80d34a94 808a6148 80d34a94 00000004 80e20700 00000000 8076974c 80469810 80c2fe3c 1000ac01 ... Call Trace: [<8048b3a4>] __dev_fwnode+0x0/0xc [<80470a78>] serial_base_ctrl_add+0xa0/0x168 [<8046fc84>] serial_core_register_port+0x1c8/0x974 [<808c6af0>] dz_init+0x74/0xc8 [<800470e0>] do_one_initcall+0x44/0x2d4 [<808b111c>] kernel_init_freeable+0x258/0x308 [<8072e434>] kernel_init+0x20/0x114 [<80049cd0>] ret_from_kernel_thread+0x14/0x1c Code: 27bd0018 03e00008 2402ffea <8c8200bc> 03e00008 00000000 27bdffc0 afbe0038 afb30024 ---[ end trace 0000000000000000 ]--- -- where a pointer is dereferenced that has been derived from a null pointer to the port's parent device. Since no device is available with legacy probing and it's not anymore a preferable way to discover devices anyway, switch the driver to using a platform device and use it as the port's parent device. Update resource handling accordingly and only request the actual span of addresses used within the slot, which will have had its resource already requested by generic platform device code. Use platform_driver_probe() not just because the DZ device is fixed with solder on board and not straightforward to remove, but foremost because the associated TTY's major device number is the same as used by the zs driver and the first driver to claim it will prevent the other one from using it. Either one DZ device or some SCC devices will be present in a given system but never both at a time, and therefore we want the major device number to be claimed by the first driver to actually successfully bind to its device and platform_driver_probe() is a way to fulfil that. An unfortunate consequence of the switch to a platform device is we now hand the console over from the bootconsole much later in the bootstrap. The firmware console handler appears good enough though to work so late and in particular with interrupts enabled. Conversely only starting the console port so late lets the reset code fully utilise our delay handlers, so switch from udelay() to fsleep() for transmitter draining so as to avoid busy-waiting for an excessive amount of time. Fixes: 84a9582fd203 ("serial: core: Start managing serial controllers to enable runtime PM") Signed-off-by: Maciej W. Rozycki <macro@orcam.me.uk> Cc: stable@vger.kernel.org # needs to use .remove_new for <= 6.10 Link: https://patch.msgid.link/alpine.DEB.2.21.2605062326540.46195@angie.orcam.me.uk Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
42 hoursserial: dz: Fix bootconsole handover lockupMaciej W. Rozycki1-24/+12
commit 7f127b2208e5e2b817243cad41fe4211a6d5a7a3 upstream. Calling dz_reset() in the course of setting up the serial device causes line parameters to be reset and the transmitter disabled. We've been lucky in that no message is usually produced to the kernel log between this call and the later call to uart_set_options() in the course of console setup done by dz_serial_console_init(), or the system would hang as the console output handler in the firmware tried to access a port the transmitter of which has been disabled and line parameters messed up. This will change with the next change to the driver, so fix dz_reset() such that line parameters are set for 9600n8 console operation as with the system firmware and the transmitter re-enabled after reset. This also means dz_pm() serves no purpose anymore, so drop it. Fixes: e6ee512f5a77 ("dz.c: Resource management") Signed-off-by: Maciej W. Rozycki <macro@orcam.me.uk> Cc: stable@vger.kernel.org # v2.6.25+ Link: https://patch.msgid.link/alpine.DEB.2.21.2605062302010.46195@angie.orcam.me.uk Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
42 hoursserial: dz: Fix bootconsole message clobbering at chip resetMaciej W. Rozycki1-0/+21
commit ca904f4b42355287bc5ce8b7550ebe909cda4c2c upstream. In the DZ interface as implemented by the DC7085 gate array the serial transmitters are double buffered, meaning that at the time a transmitter is ready to accept the next character there is one in the transmit shift register still being sent to the line. Issuing a master clear at this time causes this character to be lost, so wait an extra amount of time sufficient for the transmit shift register to drain at 9600bps, which is the baud rate setting used by the firmware console. Mind the specified 1.4us TRDY recovery time in the course and continue using iob() as the completion barrier, since the platforms involved use a write buffer that can delay and combine writes, and reorder them with respect to reads regardless of the MMIO locations accessed and we still lack a platform-independent handler for that. When called from dz_serial_console_init() this is too early for fsleep() to work and even before lpj has been calculated and therefore the delay is actually not sufficient for the transmitter to drain and is merely a placeholder now. This will be addressed in a follow-up change. Fixes: e6ee512f5a77 ("dz.c: Resource management") Signed-off-by: Maciej W. Rozycki <macro@orcam.me.uk> Cc: stable@vger.kernel.org # v2.6.25+ Link: https://patch.msgid.link/alpine.DEB.2.21.2605062259080.46195@angie.orcam.me.uk Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
42 hoursserial: fsl_lpuart: fix rx buffer and DMA map leaks in start_rx_dmaShitalkumar Gandhi1-3/+12
commit 9a9254c4a2a3ca2b3da16d173f3b0dd01f397ff6 upstream. lpuart_start_rx_dma() allocates sport->rx_ring.buf with kzalloc() and then maps a scatterlist via dma_map_sg(). On three subsequent error paths the function returns directly without releasing those resources: - when dma_map_sg() returns 0 (-EINVAL): ring->buf is leaked. - when dmaengine_slave_config() fails: ring->buf and the DMA mapping are leaked. - when dmaengine_prep_dma_cyclic() returns NULL: ring->buf and the DMA mapping are leaked. The sole cleanup path, lpuart_dma_rx_free(), is only reached when lpuart_dma_rx_use is set, and the caller lpuart_rx_dma_startup() clears that flag on failure of lpuart_start_rx_dma(). So these resources are permanently leaked on every failure in this function. Repeated port open/close or termios changes under error conditions will slowly consume memory and leave stale streaming DMA mappings behind. Fix it by introducing two error labels that unmap the scatterlist and free the ring buffer as appropriate. While here, replace the misleading -EFAULT (bad userspace pointer) returned when dmaengine_prep_dma_cyclic() fails with the more accurate -ENOMEM, matching how other dmaengine users in the tree treat this failure. No functional change on the success path. Fixes: 5887ad43ee02 ("tty: serial: fsl_lpuart: Use cyclic DMA for Rx") Cc: stable <stable@kernel.org> Signed-off-by: Shitalkumar Gandhi <shitalkumar.gandhi@cambiumnetworks.com> Reviewed-by: Frank Li <Frank.Li@nxp.com> Link: https://patch.msgid.link/20260420135903.2062024-1-shitalkumar.gandhi@cambiumnetworks.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
42 hoursserial: zs: Fix swapped RI/DSR modem line transition countingMaciej W. Rozycki1-2/+2
commit d15cd40cb1858f75846eaafa9a6bca841b790a92 upstream. Fix a thinko in the status interrupt handler that has caused counters for the RI and DSR modem line transitions to be used for the other line each. Fixes: 8b4a40809e53 ("zs: move to the serial subsystem") Cc: stable <stable@kernel.org> Signed-off-by: Maciej W. Rozycki <macro@orcam.me.uk> Link: https://patch.msgid.link/alpine.DEB.2.21.2604101747110.29980@angie.orcam.me.uk Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
42 hoursserial: sh-sci: fix memory region release in error pathHongling Zeng1-1/+1
commit 92b1ea22454b08a39baef3a7290fb3ec50366616 upstream. The sci_request_port() function uses request_mem_region() to reserve I/O memory, but in the error path when sci_remap_port() fails, it incorrectly calls release_resource() instead of release_mem_region(). This mismatch can cause resource accounting issues. Fix it by using the correct release function, consistent with sci_release_port(). Fixes: e2651647080930a1 ("serial: sh-sci: Handle port memory region reservations.") Cc: stable <stable@kernel.org> Reported-by: kernel test robot <lkp@intel.com> Reported-by: Dan Carpenter <error27@gmail.com> Closes: https://lore.kernel.org/r/202604032356.SzEjYkBC-lkp@intel.com/ Signed-off-by: Hongling Zeng <zenghongling@kylinos.cn> Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be> Link: https://patch.msgid.link/20260421065737.724187-1-zenghongling@kylinos.cn Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
42 hoursserial: qcom_geni: fix kfifo underflow when flush precedes DMA completion IRQViken Dadhaniya1-1/+13
commit 452d6fa37ae9b021f4f6d397dbae077f7296f6f4 upstream. When uart_flush_buffer() runs before the DMA completion IRQ is delivered, the following race can occur (all steps serialized by uart_port_lock): 1. DMA starts: tx_remaining = N, kfifo contains N bytes 2. DMA completes in hardware; IRQ is pending but not yet delivered 3. uart_flush_buffer() acquires the port lock and calls kfifo_reset(), making kfifo_len() = 0 while tx_remaining remains N 4. uart_flush_buffer() releases the port lock 5. DMA IRQ fires; handle_tx_dma() acquires the port lock and calls uart_xmit_advance(uport, tx_remaining) on an empty kfifo uart_xmit_advance() increments kfifo->out by tx_remaining. Since kfifo_reset() already set both in and out to 0, out wraps past in, causing kfifo_len() to return UART_XMIT_SIZE - tx_remaining. The next start_tx_dma() call then submits a DMA transfer of stale buffer data. Fix this by snapshotting kfifo_len() at the start of handle_tx_dma() and skipping uart_xmit_advance() when fifo_len < tx_remaining, which indicates the kfifo was reset by a preceding flush. Fixes: 2aaa43c70778 ("tty: serial: qcom-geni-serial: add support for serial engine DMA") Cc: stable <stable@kernel.org> Signed-off-by: Viken Dadhaniya <viken.dadhaniya@oss.qualcomm.com> Reviewed-by: Bartosz Golaszewski <bartosz.golaszewski@oss.qualcomm.com> Link: https://patch.msgid.link/20260506-serial-dma-stale-tx-buf-v1-1-e3ccb360d719@oss.qualcomm.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
42 hoursserial: qcom-geni: fix UART_RX_PAR_EN bit positionPrasanna S1-1/+1
commit ca2584d841b69391ffc4144840563d2e1a0018df upstream. UART_RX_PAR_EN is incorrectly defined as bit 3, which triggers false framing errors (S_GP_IRQ_1_EN) and causes received data to be dropped when parity is enabled and the parity bit is 0. Define UART_RX_PAR_EN as bit 4 of the SE_UART_RX_TRANS_CFG register, as specified in the reference manual. Fixes: c4f528795d1a ("tty: serial: msm_geni_serial: Add serial driver support for GENI based QUP") Cc: stable <stable@kernel.org> Signed-off-by: Prasanna S <prasanna.s@oss.qualcomm.com> Reviewed-by: Konrad Dybcio <konrad.dybcio@oss.qualcomm.com> Link: https://patch.msgid.link/20260428-serial-bit-correct-v1-1-9131ad5b97d8@oss.qualcomm.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
42 hoursserial: altera_jtaguart: handle uart_add_one_port() failuresMyeonghun Pak1-1/+6
commit ea66be25f0e934f49d24cd0c5845d13cdba3520b upstream. altera_jtaguart_probe() maps the register window before registering the UART port, but it ignores failures from uart_add_one_port(). If port registration fails, probe still returns success and the mapping remains live until a later remove path that is not part of probe failure cleanup. Return the uart_add_one_port() error and unmap the register window on that failure path. This issue was identified during our ongoing static-analysis research while reviewing kernel code. Fixes: 5bcd601049c6 ("serial: Add driver for the Altera JTAG UART") Cc: stable <stable@kernel.org> Co-developed-by: Ijae Kim <ae878000@gmail.com> Signed-off-by: Ijae Kim <ae878000@gmail.com> Signed-off-by: Myeonghun Pak <mhun512@gmail.com> Link: https://patch.msgid.link/20260512065837.79528-1-mhun512@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
42 hourstty: serial: samsung: Remove redundant port lock acquisition in rx helpersTudor Ambarus1-8/+0
commit a3bb136bff5e6a5e48cdd813246c9c4686feaaa9 upstream. Sashiko identified a deadlock when the console flow is engaged [1]. When console flow control is enabled (UPF_CONS_FLOW), s3c24xx_serial_stop_tx() calls s3c24xx_serial_rx_enable() and s3c24xx_serial_start_tx() calls s3c24xx_serial_rx_disable(). The serial core framework invokes the .stop_tx() and .start_tx() callbacks with the port->lock spinlock already held. Furthermore, all internal driver paths that invoke stop_tx (such as the DMA TX completion handler s3c24xx_serial_tx_dma_complete() or the PIO TX IRQ handler s3c24xx_serial_tx_irq()) also acquire port->lock prior to calling it. (Note that s3c24xx_serial_start_tx() is only invoked by the serial core). However, s3c24xx_serial_rx_enable() and s3c24xx_serial_rx_disable() unconditionally attempt to acquire port->lock again using uart_port_lock_irqsave(). Since spinlocks are not recursive, this causes a deadlock on the same CPU when console flow control is engaged. Remove the redundant lock acquisition from both rx helper functions. Cc: stable <stable@kernel.org> Fixes: b497549a035c ("[ARM] S3C24XX: Split serial driver into core and per-cpu drivers") Reported-by: John Ogness <john.ogness@linutronix.de> Closes: https://sashiko.dev/#/patchset/20260506121606.5805-1-john.ogness%40linutronix.de [1] Signed-off-by: Tudor Ambarus <tudor.ambarus@linaro.org> Link: https://patch.msgid.link/20260515-samsung-tty-flow-control-deadlock-v1-1-93255edbc9bc@linaro.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
42 hourstty: serial: pch_uart: add check for dma_alloc_coherent()Zhaoyang Yu1-6/+13
commit 6fe472c1bbbe238e91141f7cabc1226e96a60d43 upstream. Add a check for dma_alloc_coherent() failure to prevent a potential NULL pointer dereference in dma_handle_rx(). Properly release DMA channels and the PCI device reference using a goto ladder if the allocation fails. Fixes: 3c6a483275f4 ("Serial: EG20T: add PCH_UART driver") Cc: stable <stable@kernel.org> Signed-off-by: Zhaoyang Yu <2426767509@qq.com> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Link: https://patch.msgid.link/tencent_E328416B7CFD436F6029F2DF02AD7ED89C08@qq.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-05-23tty: serial: ip22zilog: Fix section mispatch warningThomas Bogendoerfer1-1/+1
[ Upstream commit a1a81aef99e853dec84241d701fbf587d713eb5b ] ip22zilog_prepare() is now called by driver probe routine, so it shouldn't be in the __init section any longer. Fixes: 3fc36ae6abd2 ("tty: serial: ip22zilog: Use platform device for probing") Reported-by: kernel test robot <lkp@intel.com> Closes: https://lore.kernel.org/oe-kbuild-all/202604020945.c9jAvCPs-lkp@intel.com/ Signed-off-by: Thomas Bogendoerfer <tbogendoerfer@suse.de> Link: https://patch.msgid.link/20260402102154.136620-1-tbogendoerfer@suse.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2026-05-23tty: hvc_iucv: fix off-by-one in number of supported devicesRandy Dunlap1-1/+1
[ Upstream commit f2a880e802ad12d1e38039d1334fb1475d0f5241 ] MAX_HVC_IUCV_LINES == HVC_ALLOC_TTY_ADAPTERS == 8. This is the number of entries in: static struct hvc_iucv_private *hvc_iucv_table[MAX_HVC_IUCV_LINES]; Sometimes hvc_iucv_table[] is limited by: (a) if (num > hvc_iucv_devices) // for error detection or (b) for (i = 0; i < hvc_iucv_devices; i++) // in 2 places (so these 2 don't agree; second one appears to be correct to me.) hvc_iucv_devices can be 0..8. This is a counter. (c) if (hvc_iucv_devices > MAX_HVC_IUCV_LINES) If hvc_iucv_devices == 8, (a) allows the code to access hvc_iucv_table[8]. Oops. Fixes: 44a01d5ba8a4 ("[S390] s390/hvc_console: z/VM IUCV hypervisor console support") Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Link: https://patch.msgid.link/20260130072939.1535869-1-rdunlap@infradead.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2026-03-30vt: resize saved unicode buffer on alt screen exit after resizeNicolas Pitre1-9/+15
Instead of discarding the saved unicode buffer when the console was resized while in the alternate screen, resize it to the current dimensions using vc_uniscr_copy_area() to preserve its content. This properly restores the unicode screen on alt screen exit rather than lazily rebuilding it from a lossy reverse glyph translation. On allocation failure the stale buffer is freed and vc_uni_lines is set to NULL so it gets lazily rebuilt via vc_uniscr_check() when next needed. Fixes: 40014493cece ("vt: discard stale unicode buffer on alt screen exit after resize") Cc: stable <stable@kernel.org> Signed-off-by: Nicolas Pitre <nico@fluxnic.net> Link: https://patch.msgid.link/3nsr334n-079q-125n-7807-n4nq818758ns@syhkavp.arg Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-03-30vt: discard stale unicode buffer on alt screen exit after resizeLiav Mordouch1-1/+13
When enter_alt_screen() saves vc_uni_lines into vc_saved_uni_lines and sets vc_uni_lines to NULL, a subsequent console resize via vc_do_resize() skips reallocating the unicode buffer because vc_uni_lines is NULL. However, vc_saved_uni_lines still points to the old buffer allocated for the original dimensions. When leave_alt_screen() later restores vc_saved_uni_lines, the buffer dimensions no longer match vc_rows/vc_cols. Any operation that iterates over the unicode buffer using the current dimensions (e.g. csi_J clearing the screen) will access memory out of bounds, causing a kernel oops: BUG: unable to handle page fault for address: 0x0000002000000020 RIP: 0010:csi_J+0x133/0x2d0 The faulting address 0x0000002000000020 is two adjacent u32 space characters (0x20) interpreted as a pointer, read from the row data area past the end of the 25-entry pointer array in a buffer allocated for 80x25 but accessed with 240x67 dimensions. Fix this by checking whether the console dimensions changed while in the alternate screen. If they did, free the stale saved buffer instead of restoring it. The unicode screen will be lazily rebuilt via vc_uniscr_check() when next needed. Fixes: 5eb608319bb5 ("vt: save/restore unicode screen buffer for alternate screen") Cc: stable <stable@kernel.org> Tested-by: Liav Mordouch <liavmordouch@gmail.com> Signed-off-by: Liav Mordouch <liavmordouch@gmail.com> Reviewed-by: Nicolas Pitre <nico@fluxnic.net> Link: https://patch.msgid.link/20260327170204.29706-1-liavmordouch@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-03-13vt: save/restore unicode screen buffer for alternate screenNicolas Pitre1-0/+8
The alternate screen support added by commit 23743ba64709 ("vt: add support for smput/rmput escape codes") only saves and restores the regular screen buffer (vc_origin), but completely ignores the corresponding unicode screen buffer (vc_uni_lines) creating a messed-up display. Add vc_saved_uni_lines to save the unicode screen buffer when entering the alternate screen, and restore it when leaving. Also ensure proper cleanup in reset_terminal() and vc_deallocate(). Fixes: 23743ba64709 ("vt: add support for smput/rmput escape codes") Cc: stable <stable@kernel.org> Signed-off-by: Nicolas Pitre <npitre@baylibre.com> Link: https://patch.msgid.link/5o2p6qp3-91pq-0p17-or02-1oors4417ns7@onlyvoer.pbz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-03-12serial: 8250_dw: Ensure BUSY is deassertedIlpo Järvinen3-55/+161
DW UART cannot write to LCR, DLL, and DLH while BUSY is asserted. Existance of BUSY depends on uart_16550_compatible, if UART HW is configured with it those registers can always be written. There currently is dw8250_force_idle() which attempts to achieve non-BUSY state by disabling FIFO, however, the solution is unreliable when Rx keeps getting more and more characters. Create a sequence of operations that ensures UART cannot keep BUSY asserted indefinitely. The new sequence relies on enabling loopback mode temporarily to prevent incoming Rx characters keeping UART BUSY. Ensure no Tx in ongoing while the UART is switches into the loopback mode (requires exporting serial8250_fifo_wait_for_lsr_thre() and adding DMA Tx pause/resume functions). According to tests performed by Adriana Nicolae <adriana@arista.com>, simply disabling FIFO or clearing FIFOs only once does not always ensure BUSY is deasserted but up to two tries may be needed. This could be related to ongoing Rx of a character (a guess, not known for sure). Therefore, retry FIFO clearing a few times (retry limit 4 is arbitrary number but using, e.g., p->fifosize seems overly large). Tests performed by others did not exhibit similar challenge but it does not seem harmful to leave the FIFO clearing loop in place for all DW UARTs with BUSY functionality. Use the new dw8250_idle_enter/exit() to do divisor writes and LCR writes. In case of plain LCR writes, opportunistically try to update LCR first and only invoke dw8250_idle_enter() if the write did not succeed (it has been observed that in practice most LCR writes do succeed without complications). This issue was first reported by qianfan Zhao who put lots of debugging effort into understanding the solution space. Fixes: c49436b657d0 ("serial: 8250_dw: Improve unwritable LCR workaround") Fixes: 7d4008ebb1c9 ("tty: add a DesignWare 8250 driver") Cc: stable <stable@kernel.org> Reported-by: qianfan Zhao <qianfanguijin@163.com> Link: https://lore.kernel.org/linux-serial/289bb78a-7509-1c5c-2923-a04ed3b6487d@163.com/ Reported-by: Adriana Nicolae <adriana@arista.com> Link: https://lore.kernel.org/linux-serial/20250819182322.3451959-1-adriana@arista.com/ Reported-by: Bandal, Shankar <shankar.bandal@intel.com> Tested-by: Bandal, Shankar <shankar.bandal@intel.com> Tested-by: Murthy, Shanth <shanth.murthy@intel.com> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Link: https://patch.msgid.link/20260203171049.4353-8-ilpo.jarvinen@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-03-12serial: 8250: Add late synchronize_irq() to shutdown to handle DW UART BUSYIlpo Järvinen1-0/+6
When DW UART is !uart_16550_compatible, it can indicate BUSY at any point (when under constant Rx pressure) unless a complex sequence of steps is performed. Any LCR write can run a foul with the condition that prevents writing LCR while the UART is BUSY, which triggers BUSY_DETECT interrupt that seems unmaskable using IER bits. Normal flow is that dw8250_handle_irq() handles BUSY_DETECT condition by reading USR register. This BUSY feature, however, breaks the assumptions made in serial8250_do_shutdown(), which runs synchronize_irq() after clearing IER and assumes no interrupts can occur after that point but then proceeds to update LCR, which on DW UART can trigger an interrupt. If serial8250_do_shutdown() releases the interrupt handler before the handler has run and processed the BUSY_DETECT condition by read the USR register, the IRQ is not deasserted resulting in interrupt storm that triggers "irq x: nobody cared" warning leading to disabling the IRQ. Add late synchronize_irq() into serial8250_do_shutdown() to ensure BUSY_DETECT from DW UART is handled before port's interrupt handler is released. Alternative would be to add DW UART specific shutdown function but it would mostly duplicate the generic code and the extra synchronize_irq() seems pretty harmless in serial8250_do_shutdown(). Fixes: 7d4008ebb1c9 ("tty: add a DesignWare 8250 driver") Cc: stable <stable@kernel.org> Reported-by: Bandal, Shankar <shankar.bandal@intel.com> Tested-by: Bandal, Shankar <shankar.bandal@intel.com> Tested-by: Murthy, Shanth <shanth.murthy@intel.com> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Link: https://patch.msgid.link/20260203171049.4353-7-ilpo.jarvinen@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-03-12serial: 8250_dw: Rework IIR_NO_INT handling to stop interrupt stormIlpo Järvinen1-4/+63
INTC10EE UART can end up into an interrupt storm where it reports IIR_NO_INT (0x1). If the storm happens during active UART operation, it is promptly stopped by IIR value change due to Rx or Tx events. However, when there is no activity, either due to idle serial line or due to specific circumstances such as during shutdown that writes IER=0, there is nothing to stop the storm. During shutdown the storm is particularly problematic because serial8250_do_shutdown() calls synchronize_irq() that will hang in waiting for the storm to finish which never happens. This problem can also result in triggering a warning: irq 45: nobody cared (try booting with the "irqpoll" option) [...snip...] handlers: serial8250_interrupt Disabling IRQ #45 Normal means to reset interrupt status by reading LSR, MSR, USR, or RX register do not result in the UART deasserting the IRQ. Add a quirk to INTC10EE UARTs to enable Tx interrupts if UART's Tx is currently empty and inactive. Rework IIR_NO_INT to keep track of the number of consecutive IIR_NO_INT, and on fourth one perform the quirk. Enabling Tx interrupts should change IIR value from IIR_NO_INT to IIR_THRI which has been observed to stop the storm. Fixes: e92fad024929 ("serial: 8250_dw: Add ACPI ID for Granite Rapids-D UART") Cc: stable <stable@kernel.org> Reported-by: Bandal, Shankar <shankar.bandal@intel.com> Tested-by: Bandal, Shankar <shankar.bandal@intel.com> Tested-by: Murthy, Shanth <shanth.murthy@intel.com> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Link: https://patch.msgid.link/20260203171049.4353-6-ilpo.jarvinen@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-03-12serial: 8250_dw: Rework dw8250_handle_irq() locking and IIR handlingIlpo Järvinen1-16/+21
dw8250_handle_irq() takes port's lock multiple times with no good reason to release it in between and calls serial8250_handle_irq() that also takes port's lock. Take port's lock only once in dw8250_handle_irq() and use serial8250_handle_irq_locked() to avoid releasing port's lock in between. As IIR_NO_INT check in serial8250_handle_irq() was outside of port's lock, it has to be done already in dw8250_handle_irq(). DW UART can, in addition to IIR_NO_INT, report BUSY_DETECT (0x7) which collided with the IIR_NO_INT (0x1) check in serial8250_handle_irq() (because & is used instead of ==) meaning that no other work is done by serial8250_handle_irq() during an BUSY_DETECT interrupt. This allows reorganizing code in dw8250_handle_irq() to do both IIR_NO_INT and BUSY_DETECT handling right at the start simplifying the logic. Tested-by: Bandal, Shankar <shankar.bandal@intel.com> Tested-by: Murthy, Shanth <shanth.murthy@intel.com> Cc: stable <stable@kernel.org> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Link: https://patch.msgid.link/20260203171049.4353-5-ilpo.jarvinen@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-03-12serial: 8250: Add serial8250_handle_irq_locked()Ilpo Järvinen1-8/+16
8250_port exports serial8250_handle_irq() to HW specific 8250 drivers. It takes port's lock within but a HW specific 8250 driver may want to take port's lock itself, do something, and then call the generic handler in 8250_port but to do that, the caller has to release port's lock for no good reason. Introduce serial8250_handle_irq_locked() which a HW specific driver can call while already holding port's lock. As this is new export, put it straight into a namespace (where all 8250 exports should eventually be moved). Tested-by: Bandal, Shankar <shankar.bandal@intel.com> Tested-by: Murthy, Shanth <shanth.murthy@intel.com> Cc: stable <stable@kernel.org> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Link: https://patch.msgid.link/20260203171049.4353-4-ilpo.jarvinen@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-03-12serial: 8250_dw: Avoid unnecessary LCR writesIlpo Järvinen1-0/+31
When DW UART is configured with BUSY flag, LCR writes may not always succeed which can make any LCR write complex and very expensive. Performing write directly can trigger IRQ and the driver has to perform complex and distruptive sequence while retrying the write. Therefore, it's better to avoid doing LCR write that would not change the value of the LCR register. Add LCR write avoidance code into the 8250_dw driver's .serial_out() functions. Reported-by: Bandal, Shankar <shankar.bandal@intel.com> Tested-by: Bandal, Shankar <shankar.bandal@intel.com> Tested-by: Murthy, Shanth <shanth.murthy@intel.com> Cc: stable <stable@kernel.org> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Link: https://patch.msgid.link/20260203171049.4353-3-ilpo.jarvinen@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-03-12serial: 8250: Protect LCR write in shutdownIlpo Järvinen1-5/+6
The 8250_dw driver needs to potentially perform very complex operations during LCR writes because its BUSY handling prevents updates to LCR while UART is BUSY (which is not fully under our control without those complex operations). Thus, LCR writes should occur under port's lock. Move LCR write under port's lock in serial8250_do_shutdown(). Also split the LCR RMW so that the logic is on a separate line for clarity. Reported-by: Bandal, Shankar <shankar.bandal@intel.com> Tested-by: Bandal, Shankar <shankar.bandal@intel.com> Tested-by: Murthy, Shanth <shanth.murthy@intel.com> Cc: stable <stable@kernel.org> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Link: https://patch.msgid.link/20260203171049.4353-2-ilpo.jarvinen@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-03-12serial: 8250_pci: add support for the AX99100Martin Roukala (né Peres)1-0/+17
This is found in popular brands such as StarTech.com or Delock, and has been a source of frustration to quite a few people, if I can trust Amazon comments complaining about Linux support via the official out-of-the-tree driver. Signed-off-by: Martin Roukala (né Peres) <martin.roukala@mupuf.org> Cc: stable <stable@kernel.org> Link: https://patch.msgid.link/20260309-8250_pci_ax99100-v1-1-3328bdfd8e94@mupuf.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-03-12serial: core: fix infinite loop in handle_tx() for PORT_UNKNOWNJiayuan Chen1-1/+4
uart_write_room() and uart_write() behave inconsistently when xmit_buf is NULL (which happens for PORT_UNKNOWN ports that were never properly initialized): - uart_write_room() returns kfifo_avail() which can be > 0 - uart_write() checks xmit_buf and returns 0 if NULL This inconsistency causes an infinite loop in drivers that rely on tty_write_room() to determine if they can write: while (tty_write_room(tty) > 0) { written = tty->ops->write(...); // written is always 0, loop never exits } For example, caif_serial's handle_tx() enters an infinite loop when used with PORT_UNKNOWN serial ports, causing system hangs. Fix by making uart_write_room() also check xmit_buf and return 0 if it's NULL, consistent with uart_write(). Reproducer: https://gist.github.com/mrpre/d9a694cc0e19828ee3bc3b37983fde13 Signed-off-by: Jiayuan Chen <jiayuan.chen@shopee.com> Cc: stable <stable@kernel.org> Link: https://patch.msgid.link/20260204074327.226165-1-jiayuan.chen@linux.dev Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-03-12serial: uartlite: fix PM runtime usage count underflow on probeMaciej Andrzejewski ICEYE1-0/+1
ulite_probe() calls pm_runtime_put_autosuspend() at the end of probe without holding a corresponding PM runtime reference for non-console ports. During ulite_assign(), uart_add_one_port() triggers uart_configure_port() which calls ulite_pm() via uart_change_pm(). For non-console ports, the UART core performs a balanced get/put cycle: uart_change_pm(ON) -> ulite_pm() -> pm_runtime_get_sync() +1 uart_change_pm(OFF) -> ulite_pm() -> pm_runtime_put_autosuspend() -1 This leaves no spare reference for the pm_runtime_put_autosuspend() at the end of probe. The PM runtime core prevents the count from actually going below zero, and instead triggers a "Runtime PM usage count underflow!" warning. For console ports the bug is masked: the UART core skips the uart_change_pm(OFF) call, so the UART core's unbalanced get happens to pair with probe's trailing put. Add pm_runtime_get_noresume() before pm_runtime_enable() to take an explicit probe-owned reference that the trailing pm_runtime_put_autosuspend() can release. This ensures a correct usage count regardless of whether the port is a console. Fixes: 5bbe10a6942d ("tty: serial: uartlite: Add runtime pm support") Cc: stable <stable@kernel.org> Signed-off-by: Maciej Andrzejewski ICEYE <maciej.andrzejewski@m-works.net> Link: https://patch.msgid.link/20260305123746.4152800-1-maciej.andrzejewski@m-works.net Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-03-12serial: 8250: always disable IRQ during THRE testPeng Zhang1-4/+2
commit 039d4926379b ("serial: 8250: Toggle IER bits on only after irq has been set up") moved IRQ setup before the THRE test, in combination with commit 205d300aea75 ("serial: 8250: change lock order in serial8250_do_startup()") the interrupt handler can run during the test and race with its IIR reads. This can produce wrong THRE test results and cause spurious registration of the serial8250_backup_timeout timer. Unconditionally disable the IRQ for the short duration of the test and re-enable it afterwards to avoid the race. Fixes: 039d4926379b ("serial: 8250: Toggle IER bits on only after irq has been set up") Depends-on: 205d300aea75 ("serial: 8250: change lock order in serial8250_do_startup()") Cc: stable <stable@kernel.org> Signed-off-by: Peng Zhang <zhangpeng.00@bytedance.com> Reviewed-by: Muchun Song <songmuchun@bytedance.com> Signed-off-by: Alban Bedel <alban.bedel@lht.dlh.de> Tested-by: Maximilian Lueer <maximilian.lueer@lht.dlh.de> Link: https://patch.msgid.link/20260224121639.579404-1-alban.bedel@lht.dlh.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-03-12serial: 8250: Fix TX deadlock when using DMARaul E Rangel1-0/+15
`dmaengine_terminate_async` does not guarantee that the `__dma_tx_complete` callback will run. The callback is currently the only place where `dma->tx_running` gets cleared. If the transaction is canceled and the callback never runs, then `dma->tx_running` will never get cleared and we will never schedule new TX DMA transactions again. This change makes it so we clear `dma->tx_running` after we terminate the DMA transaction. This is "safe" because `serial8250_tx_dma_flush` is holding the UART port lock. The first thing the callback does is also grab the UART port lock, so access to `dma->tx_running` is serialized. Fixes: 9e512eaaf8f4 ("serial: 8250: Fix fifo underflow on flush") Cc: stable <stable@kernel.org> Signed-off-by: Raul E Rangel <rrangel@google.com> Link: https://patch.msgid.link/20260209135815.1.I16366ecb0f62f3c96fe3dd5763fcf6f3c2b4d8cd@changeid Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-02-22Convert remaining multi-line kmalloc_obj/flex GFP_KERNEL usesKees Cook1-1/+1
Conversion performed via this Coccinelle script: // SPDX-License-Identifier: GPL-2.0-only // Options: --include-headers-for-types --all-includes --include-headers --keep-comments virtual patch @gfp depends on patch && !(file in "tools") && !(file in "samples")@ identifier ALLOC = {kmalloc_obj,kmalloc_objs,kmalloc_flex, kzalloc_obj,kzalloc_objs,kzalloc_flex, kvmalloc_obj,kvmalloc_objs,kvmalloc_flex, kvzalloc_obj,kvzalloc_objs,kvzalloc_flex}; @@ ALLOC(... - , GFP_KERNEL ) $ make coccicheck MODE=patch COCCI=gfp.cocci Build and boot tested x86_64 with Fedora 42's GCC and Clang: Linux version 6.19.0+ (user@host) (gcc (GCC) 15.2.1 20260123 (Red Hat 15.2.1-7), GNU ld version 2.44-12.fc42) #1 SMP PREEMPT_DYNAMIC 1970-01-01 Linux version 6.19.0+ (user@host) (clang version 20.1.8 (Fedora 20.1.8-4.fc42), LLD 20.1.8) #1 SMP PREEMPT_DYNAMIC 1970-01-01 Signed-off-by: Kees Cook <kees@kernel.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2026-02-22Convert more 'alloc_obj' cases to default GFP_KERNEL argumentsLinus Torvalds6-14/+7
This converts some of the visually simpler cases that have been split over multiple lines. I only did the ones that are easy to verify the resulting diff by having just that final GFP_KERNEL argument on the next line. Somebody should probably do a proper coccinelle script for this, but for me the trivial script actually resulted in an assertion failure in the middle of the script. I probably had made it a bit _too_ trivial. So after fighting that far a while I decided to just do some of the syntactically simpler cases with variations of the previous 'sed' scripts. The more syntactically complex multi-line cases would mostly really want whitespace cleanup anyway. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2026-02-22Convert 'alloc_flex' family to use the new default GFP_KERNEL argumentLinus Torvalds3-3/+3
This is the exact same thing as the 'alloc_obj()' version, only much smaller because there are a lot fewer users of the *alloc_flex() interface. As with alloc_obj() version, this was done entirely with mindless brute force, using the same script, except using 'flex' in the pattern rather than 'objs*'. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2026-02-22Convert 'alloc_obj' family to use the new default GFP_KERNEL argumentLinus Torvalds41-55/+55
This was done entirely with mindless brute force, using git grep -l '\<k[vmz]*alloc_objs*(.*, GFP_KERNEL)' | xargs sed -i 's/\(alloc_objs*(.*\), GFP_KERNEL)/\1)/' to convert the new alloc_obj() users that had a simple GFP_KERNEL argument to just drop that argument. Note that due to the extreme simplicity of the scripting, any slightly more complex cases spread over multiple lines would not be triggered: they definitely exist, but this covers the vast bulk of the cases, and the resulting diff is also then easier to check automatically. For the same reason the 'flex' versions will be done as a separate conversion. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2026-02-21treewide: Replace kmalloc with kmalloc_obj for non-scalar typesKees Cook51-86/+84
This is the result of running the Coccinelle script from scripts/coccinelle/api/kmalloc_objs.cocci. The script is designed to avoid scalar types (which need careful case-by-case checking), and instead replace kmalloc-family calls that allocate struct or union object instances: Single allocations: kmalloc(sizeof(TYPE), ...) are replaced with: kmalloc_obj(TYPE, ...) Array allocations: kmalloc_array(COUNT, sizeof(TYPE), ...) are replaced with: kmalloc_objs(TYPE, COUNT, ...) Flex array allocations: kmalloc(struct_size(PTR, FAM, COUNT), ...) are replaced with: kmalloc_flex(*PTR, FAM, COUNT, ...) (where TYPE may also be *VAR) The resulting allocations no longer return "void *", instead returning "TYPE *". Signed-off-by: Kees Cook <kees@kernel.org>
2026-02-17Merge tag 'tty-7.0-rc1' of ↵Linus Torvalds16-339/+641
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty Pull tty / serial driver updates from Greg KH: "Here is the small amount of tty and serial driver updates for 7.0-rc1. Nothing major in here at all, just some driver updates and minor tweaks and cleanups including: - sh-sci serial driver updates - 8250 driver updates - attempt to make the tty ports have their own workqueue, but was reverted after testing found it to have problems on some platforms. This will probably come back for 7.1 after it has been reworked and resubmitted - other tiny tty driver changes All of these have been in linux-next for a while with no reported problems" * tag 'tty-7.0-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: (49 commits) Revert "tty: tty_port: add workqueue to flip TTY buffer" tty: tty_port: add workqueue to flip TTY buffer serial: 8250_pci: Remove custom deprecated baud setting routine serial: 8250_omap: Remove custom deprecated baud setting routine dt-bindings: serial: renesas,scif: Document RZ/G3L SoC serial: 8250: omap: set out-of-band wakeup if wakeup pinctrl exists tty: hvc-iucv: Remove KMSG_COMPONENT macro dt-bindings: serial: google,goldfish-tty: Convert to DT schema dt-bindings: serial: sh-sci: Fold single-entry compatibles into enum serial: 8250: 8250_omap.c: Clear DMA RX running status only after DMA termination is done serial: 8250: 8250_omap.c: Add support for handling UART error conditions serial: SH_SCI: improve "DMA support" prompt serial: Kconfig: fix ordering of entries for menu display serial: 8250: fix ordering of entries for menu display serial: imx: change SERIAL_IMX_CONSOLE to bool 8250_men_mcb: drop unneeded MODULE_ALIAS serial: men_z135_uart: drop unneeded MODULE_ALIAS dt-bindings: serial: renesas,rsci: Document RZ/V2H(P) and RZ/V2N SoCs serial: rsci: Convert to FIELD_MODIFY() dt-bindings: serial: 8250: add SpacemiT K3 UART compatible ...
2026-02-16Merge tag 'mips_7.0' of git://git.kernel.org/pub/scm/linux/kernel/git/mips/linuxLinus Torvalds1-2/+1
Pull MIPS updates from Thomas Bogendoerfer: "Cleanups and fixes" * tag 'mips_7.0' of git://git.kernel.org/pub/scm/linux/kernel/git/mips/linux: (28 commits) Revert "clk: microchip: core: allow driver to be compiled with COMPILE_TEST" Revert "clk: microchip: fix typo in reference to a config option" MIPS: Implement ARCH_HAS_CC_CAN_LINK MIPS: rb532: Fix MMIO UART resource registration MIPS: Work around LLVM bug when gp is used as global register variable MIPS: Loongson64: env: Fixup serial clock-frequency when using LEFI MIPS: Loongson2ef: Use pcibios_align_resource() to block io range MIPS: Loongson2ef: Register PCI controller in early stage clk: microchip: fix typo in reference to a config option MIPS: Loongson64: dts: fix phy-related definition of LS7A GMAC clk: microchip: core: allow driver to be compiled with COMPILE_TEST MIPS: drop unused pic32.h header watchdog: pic32-wdt: update include to use pic32.h from platform_data watchdog: pic32-dmt: update include to use pic32.h from platform_data serial: pic32_uart: update include to use pic32.h from platform_data rtc: pic32: update include to use pic32.h from platform_data pinctrl: pic32: update include to use pic32.h from platform_data mmc: sdhci-pic32: update include to use pic32.h from platform_data irqchip/irq-pic32-evic: update include to use pic32.h from platform_data clk: microchip: core: update include to use pic32.h from platform_data ...
2026-02-14printk, vt, fbcon: Remove console_conditional_schedule()Sebastian Andrzej Siewior1-1/+0
do_con_write(), fbcon_redraw.*() invoke console_conditional_schedule() which is a conditional scheduling point based on printk's internal variables console_may_schedule. It may only be used if the console lock is acquired for instance via console_lock() or console_trylock(). Prinkt sets the internal variable to 1 (and allows to schedule) if the console lock has been acquired via console_lock(). The trylock does not allow it. The console_conditional_schedule() invocation in do_con_write() is invoked shortly before console_unlock(). The console_conditional_schedule() invocation in fbcon_redraw.*() original from fbcon_scroll() / vt's con_scroll() which originate from a line feed. In console_unlock() the variable is set to 0 (forbids to schedule) and it tries to schedule while making progress printing. This is brand new compared to when console_conditional_schedule() was added in v2.4.9.11. In v2.6.38-rc3, console_unlock() (started its existence) iterated over all consoles and flushed them with disabled interrupts. A scheduling attempt here was not possible, it relied that a long print scheduled before console_unlock(). Since commit 8d91f8b15361d ("printk: do cond_resched() between lines while outputting to consoles"), which appeared in v4.5-rc1, console_unlock() attempts to schedule if it was allowed to schedule while during console_lock(). Each record is idealy one line so after every line feed. This console_conditional_schedule() is also only relevant on PREEMPT_NONE and PREEMPT_VOLUNTARY builds. In other configurations cond_resched() becomes a nop and has no impact. I'm bringing this all up just proof that it is not required anymore. It becomes a problem on a PREEMPT_RT build with debug code enabled because that might_sleep() in cond_resched() remains and triggers a warnings. This is due to legacy_kthread_func-> console_flush_one_record -> vt_console_print-> lf -> con_scroll -> fbcon_scroll and vt_console_print() acquires a spinlock_t which does not allow a voluntary schedule. There is no need to fb_scroll() to schedule since console_flush_one_record() attempts to schedule after each line. !PREEMPT_RT is not affected because the legacy printing thread is only enabled on PREEMPT_RT builds. Therefore I suggest to remove console_conditional_schedule(). Cc: Simona Vetter <simona@ffwll.ch> Cc: Helge Deller <deller@gmx.de> Cc: linux-fbdev@vger.kernel.org Cc: dri-devel@lists.freedesktop.org Fixes: 5f53ca3ff83b4 ("printk: Implement legacy printer kthread for PREEMPT_RT") Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Acked-by: Petr Mladek <pmladek@suse.com> # from printk() POV Signed-off-by: Helge Deller <deller@gmx.de>
2026-02-12Merge tag 'mm-nonmm-stable-2026-02-12-10-48' of ↵Linus Torvalds1-0/+1
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Pull non-MM updates from Andrew Morton: - "ocfs2: give ocfs2 the ability to reclaim suballocator free bg" saves disk space by teaching ocfs2 to reclaim suballocator block group space (Heming Zhao) - "Add ARRAY_END(), and use it to fix off-by-one bugs" adds the ARRAY_END() macro and uses it in various places (Alejandro Colomar) - "vmcoreinfo: support VMCOREINFO_BYTES larger than PAGE_SIZE" makes the vmcore code future-safe, if VMCOREINFO_BYTES ever exceeds the page size (Pnina Feder) - "kallsyms: Prevent invalid access when showing module buildid" cleans up kallsyms code related to module buildid and fixes an invalid access crash when printing backtraces (Petr Mladek) - "Address page fault in ima_restore_measurement_list()" fixes a kexec-related crash that can occur when booting the second-stage kernel on x86 (Harshit Mogalapalli) - "kho: ABI headers and Documentation updates" updates the kexec handover ABI documentation (Mike Rapoport) - "Align atomic storage" adds the __aligned attribute to atomic_t and atomic64_t definitions to get natural alignment of both types on csky, m68k, microblaze, nios2, openrisc and sh (Finn Thain) - "kho: clean up page initialization logic" simplifies the page initialization logic in kho_restore_page() (Pratyush Yadav) - "Unload linux/kernel.h" moves several things out of kernel.h and into more appropriate places (Yury Norov) - "don't abuse task_struct.group_leader" removes the usage of ->group_leader when it is "obviously unnecessary" (Oleg Nesterov) - "list private v2 & luo flb" adds some infrastructure improvements to the live update orchestrator (Pasha Tatashin) * tag 'mm-nonmm-stable-2026-02-12-10-48' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (107 commits) watchdog/hardlockup: simplify perf event probe and remove per-cpu dependency procfs: fix missing RCU protection when reading real_parent in do_task_stat() watchdog/softlockup: fix sample ring index wrap in need_counting_irqs() kcsan, compiler_types: avoid duplicate type issues in BPF Type Format kho: fix doc for kho_restore_pages() tests/liveupdate: add in-kernel liveupdate test liveupdate: luo_flb: introduce File-Lifecycle-Bound global state liveupdate: luo_file: Use private list list: add kunit test for private list primitives list: add primitives for private list manipulations delayacct: fix uapi timespec64 definition panic: add panic_force_cpu= parameter to redirect panic to a specific CPU netclassid: use thread_group_leader(p) in update_classid_task() RDMA/umem: don't abuse current->group_leader drm/pan*: don't abuse current->group_leader drm/amd: kill the outdated "Only the pthreads threading model is supported" checks drm/amdgpu: don't abuse current->group_leader android/binder: use same_thread_group(proc->tsk, current) in binder_mmap() android/binder: don't abuse current->group_leader kho: skip memoryless NUMA nodes when reserving scratch areas ...
2026-02-11Merge tag 'drm-next-2026-02-11' of https://gitlab.freedesktop.org/drm/kernelLinus Torvalds1-30/+2
Pull drm updates from Dave Airlie: "Highlights: - amdgpu support for lots of new IP blocks which means newer GPUs - xe has a lot of SR-IOV and SVM improvements - lots of intel display refactoring across i915/xe - msm has more support for gen8 platforms - Given up on kgdb/kms integration, it's too hard on modern hw core: - drop kgdb support - replace system workqueue with percpu - account for property blobs in memcg - MAINTAINERS updates for xe + buddy rust: - Fix documentation for Registration constructors - Use pin_init::zeroed() for fops initialization - Annotate DRM helpers with __rust_helper - Improve safety documentation for gem::Object::new() - Update AlwaysRefCounted imports - mm: Prevent integer overflow in page_align() atomic: - add drm_device pointer to drm_private_obj - introduce gamma/degamma LUT size check buddy: - fix free_trees memory leak - prevent BUG_ON bridge: - introduce drm_bridge_unplug/enter/exit - add connector argument to .hpd_notify - lots of recounting conversions - convert rockchip inno hdmi to bridge - lontium-lt9611uxc: switch to HDMI audio helpers - dw-hdmi-qp: add support for HPD-less setups - Algoltek AG6311 support panels: - edp: CSW MNE007QB3-1, AUO B140HAN06.4, AUO B140QAX01.H - st75751: add SPI support - Sitronix ST7920, Samsung LTL106HL02 - LG LH546WF1-ED01, HannStar HSD156J - BOE NV130WUM-T08 - Innolux G150XGE-L05 - Anbernic RG-DS dma-buf: - improve sg_table debugging - add tracepoints - call clear_page instead of memset - start to introduce cgroup memory accounting in heaps - remove sysfs stats dma-fence: - add new helpers dp: - mst: avoid oob access with vcpi=0 hdmi: - limit infoframes exposure to userspace gem: - reduce page table overhead with THP - fix leak in drm_gem_get_unmapped_area gpuvm: - API sanitation for rust bindings sched: - introduce new helpers panic: - report invalid panic modes - add kunit tests i915/xe display: - Expose sharpness only if num_scalers is >= 2 - Add initial Xe3P_LPD for NVL - BMG FBC support - Add MTL+ platforms to support dpll framework _ fix DIMM_S DRM decoding on ICL - Return to using AUX interrupts - PSR/Panel replay refactoring - use consolidation HDMI tables - Xe3_LPD CD2X dividier changes xe: - vfio: add vfio_pci for intel GPU - multi queue support - dynamic pagemaps and multi-device SVM - expose temp attribs in hwmon - NO_COMPRESSION bo flag - expose MERT OA unit - sysfs survivability refactor - SRIOV PF: add MERT support - enable SR-IOV VF migration - Enable I2C/NVM on Crescent Island - Xe3p page reclaimation support - introduce SRIOV scheduler groups - add SoC remappt support in system controller - insert compiler barriers in GuC code - define NVL GuC firmware - handle GT resume failure - fix drm scheduler layering violations - enable GSC loading and PXP for PTL - disable GuC Power DCC strategy on PTL - unregister drm device on probe error i915: - move to kernel standard fault injection - bump recommended GuC version for DG2 and MTL amdgpu: - SMUIO 15.x, PSP 15.x support - IH 6.1.1/7.1 support - MMHUB 3.4/4.2 support - GC 11.5.4/12.1 support - SDMA 6.1.4/7.1/7.11.4 support - JPEG 5.3 support - UserQ updates - GC 9 gfx queue reset support - TTM memory ops parallelization - convert legacy logging to new helpers - DC analog fixes amdkfd: - GC 11.5.4/12.1 suppport - SDMA 6.1.4/7.1 support - per context support - increase kfd process hash table - Reserved SDMA rework radeon: - convert legacy logging to new helpers - use devm for i2c adapters msm: - GPU - Document a612/RGMU dt bindings - UBWC 6.0 support (for A840 / Kaanapali) - a225 support - DPU: - Switch to use virtual planes by default - Fix DSI CMD panels on DPU 3.x - Rewrite format handling to remove intermediate representation - Fix watchdog on DPU 8.x+ - Fix TE / Vsync source setting on DPU 8.x+ - Add 3D_Mux on SC7280 - Kaanapali platform support - Fix UBWC register programming - Make RM reserve DSPP-enabled mixers for CRTCs with LMs - Gamma correction support - DP: - Enable support for eDP 1.4+ link rate tables - Fix MDSS1 DP indices on SA8775P, making them to work - Fix msm_dp_ctrl_config_msa() to work with LLVM 20 - DSI: - Document QCS8300 as compatible with SA8775P - Kaanapali platform support - DSI PHY: - switch to divider_determine_rate() - MDP5: - Drop support for MSM8998, SDM660 and SDM630 (switch over to DPU) - MDSS: - Kaanapali platform support - Fixed UBWC register programming nova-core: - Prepare for Turing support. This includes parsing and handling Turing-specific firmware headers and sections as well as a Turing Falcon HAL implementation - Get rid of the Result<impl PinInit<T, E>> anti-pattern - Relocate initializer-specific code into the appropriate initializer - Use CStr::from_bytes_until_nul() to remove custom helpers - Improve handling of unexpected firmware values - Clean up redundant debug prints - Replace c_str!() with native Rust C-string literals - Update nova-core task list nova: - Align GEM object size to system page size tyr: - Use generated uAPI bindings for GpuInfo - Replace manual sleeps with read_poll_timeout() - Replace c_str!() with native Rust C-string literals - Suppress warnings for unread fields - Fix incorrect register name in print statement nouveau: - fix big page table support races in PTE management - improve reclocking on tegra 186+ amdxdna: - fix suspend race conditions - improve handling of zero tail pointers - fix cu_idx overwritten during command setup - enable hardware context priority - remove NPU2 support - update message buffer allocation requirements - update firmware version check ast: - support imported cursor buffers - big endian fixes etnaviv: - add PPU flop reset support imagination: - add AM62P support - introduce hw version checks ivpu: - implement warm boot flow panfrost: - add bo sync ioctl - add GPU_PM_RT support for RZ/G3E SoC panthor: - add bo sync ioctl - enable timestamp propagation - scheduler robustness improvements - VM termination fixes - huge page support rockchip: - RK3368 HDMI Support - get rid of atomic_check fixups - RK3506 support - RK3576/RK3588 improved HPD handling rz-du: - RZ/V2H(P) MIPI-DSI Support v3d: - fix DMA segment size - convert to new logging helpers mediatek: - move DP training to hotplug thread - convert logging to new helpers - add support for HS speed DSI - Genio 510/700/1200-EVK, Radxa NIO-12L HDMI support atmel-hlcdc: - switch to drmm resource - support nomodeset - use newer helpers hisilicon: - fix various DP bugs renesas: - fix kernel panic on reboot exynos: - fix vidi_connection_ioctl using wrong device - fix vidi_connection deref user ptr - fix concurrency regression with vidi_context vkms: - add configfs support for display configuration * tag 'drm-next-2026-02-11' of https://gitlab.freedesktop.org/drm/kernel: (1610 commits) drm/xe/pm: Disable D3Cold for BMG only on specific platforms drm/xe: Fix kerneldoc for xe_tlb_inval_job_alloc_dep drm/xe: Fix kerneldoc for xe_gt_tlb_inval_init_early drm/xe: Fix kerneldoc for xe_migrate_exec_queue drm/xe/query: Fix topology query pointer advance drm/xe/guc: Fix kernel-doc warning in GuC scheduler ABI header drm/xe/guc: Fix CFI violation in debugfs access. accel/amdxdna: Move RPM resume into job run function accel/amdxdna: Fix incorrect DPM level after suspend/resume nouveau/vmm: start tracking if the LPT PTE is valid. (v6) nouveau/vmm: increase size of vmm pte tracker struct to u32 (v2) nouveau/vmm: rewrite pte tracker using a struct and bitfields. accel/amdxdna: Fix incorrect error code returned for failed chain command accel/amdxdna: Remove hardware context status drm/bridge: imx8qxp-pixel-combiner: Fix bailout for imx8qxp_pc_bridge_probe() drm/panel: ilitek-ili9882t: Remove duplicate initializers in tianma_il79900a_dsc drm/i915/display: fix the pixel normalization handling for xe3p_lpd drm/exynos: vidi: use ctx->lock to protect struct vidi_context member variables related to memory alloc/free drm/exynos: vidi: fix to avoid directly dereferencing user pointer drm/exynos: vidi: use priv->vidi_dev for ctx lookup in vidi_connection_ioctl() ...
2026-02-10Merge tag 'for-linus-7.0-rc1-tag' of ↵Linus Torvalds1-5/+24
git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip Pull xen updates from Juergen Gross: - fix running as Xen PVH guest in 32-bit mode without PAE - fix PV device handling for suspend/resume when running as a Xen guest - clean up workqueue usage - fix the Xen balloon driver for PVH dom0 - introduce the possibility to use hypercalls for console messages in unprivileged guests - enable Xen dom0 use of virtio devices in nested virtualization setups - simplify the xen-mcelog driver * tag 'for-linus-7.0-rc1-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip: xenbus: Rename helpers to freeze/thaw/restore xenbus: Use .freeze/.thaw to handle xenbus devices xen/mcelog: simplify MCE_GETCLEAR_FLAGS using xchg() xen/balloon: improve accuracy of initial balloon target for dom0 Partial revert "x86/xen: fix balloon target initialization for PVH dom0" xen: introduce xen_console_io option xen/virtio: Don't use grant-dma-ops when running as Dom0 x86/xen/pvh: Enable PAE mode for 32-bit guest only when CONFIG_X86_PAE is set xen: privcmd: WQ_PERCPU added to alloc_workqueue users xen/events: replace use of system_wq with system_percpu_wq
2026-01-30serial: pic32_uart: update include to use pic32.h from platform_dataBrian Masney1-2/+1
Use the linux/platform_data/pic32.h include instead of asm/mach-pic32/pic32.h so that the asm variant can be dropped. This is in preparation for allowing some drivers to be compiled on other architectures with COMPILE_TEST enabled. Signed-off-by: Brian Masney <bmasney@redhat.com> Reviewed-by: Jiri Slaby <jirislaby@kernel.org> Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
2026-01-28BackMerge tag 'v6.19-rc7' into drm-nextDave Airlie7-22/+30
Linux 6.19-rc7 This is needed for msm and rust trees. Signed-off-by: Dave Airlie <airlied@redhat.com>
2026-01-27Revert "tty: tty_port: add workqueue to flip TTY buffer"Greg Kroah-Hartman4-57/+9
This reverts commit d000422a46aad32217cf1be747eb61d641baae2f. It is reported by many to cause boot failures, so must be reverted. Cc: Xin Zhao <jackzxcui1989@163.com> Cc: Jiri Slaby <jirislaby@kernel.org> Link: https://lore.kernel.org/r/d1942304-ee30-478d-90fb-279519f3ae81@samsung.com Reported-by: Marek Szyprowski <m.szyprowski@samsung.com> Reported-by: Tommaso Merciai <tommaso.merciai.xr@bp.renesas.com> Reported-by: Geert Uytterhoeven <geert@linux-m68k.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-01-23tty: tty_port: add workqueue to flip TTY bufferXin Zhao4-9/+57
On the embedded platform, certain critical data, such as IMU data, is transmitted through UART. The tty_flip_buffer_push() interface in the TTY layer uses system_dfl_wq to handle the flipping of the TTY buffer. Although the unbound workqueue can create new threads on demand and wake up the kworker thread on an idle CPU, it may be preempted by real-time tasks or other high-prio tasks. flush_to_ldisc() needs to wake up the relevant data handle thread. When executing __wake_up_common_lock(), it calls spin_lock_irqsave(), which does not disable preemption but disables migration in RT-Linux. This prevents the kworker thread from being migrated to other cores by CPU's balancing logic, resulting in long delays. The call trace is as follows: __wake_up_common_lock __wake_up ep_poll_callback __wake_up_common __wake_up_common_lock __wake_up n_tty_receive_buf_common n_tty_receive_buf2 tty_ldisc_receive_buf tty_port_default_receive_buf flush_to_ldisc In our system, the processing interval for each frame of IMU data transmitted via UART can experience significant jitter due to this issue. Instead of the expected 10 to 15 ms frame processing interval, we see spikes up to 30 to 35 ms. Moreover, in just one or two hours, there can be 2 to 3 occurrences of such high jitter, which is quite frequent. This jitter exceeds the software's tolerable limit of 20 ms. Introduce flip_wq in tty_port which can be set by tty_port_link_wq() or as default linked to default workqueue allocated when tty_register_driver(). The default workqueue is allocated with flag WQ_SYSFS, so that cpumask and nice can be set dynamically. The execution timing of tty_port_link_wq() is not clearly restricted. The newly added function tty_port_link_driver_wq() checks whether the flip_wq of the tty_port has already been assigned when linking the default tty_driver's workqueue to the port. After the user has set a custom workqueue for a certain tty_port using tty_port_link_wq(), the system will only use this custom workqueue, even if tty_driver does not have %TTY_DRIVER_CUSTOM_WORKQUEUE flag. Introduce %TTY_DRIVER_CUSTOM_WORKQUEUE flag meaning not to create the default single tty_driver workqueue. Two reasons why need to introduce the %TTY_DRIVER_CUSTOM_WORKQUEUE flag: 1. If the WQ_SYSFS parameter is enabled, workqueue_sysfs_register() will fail when trying to create a workqueue with the same name. The pty is an example of this; if both CONFIG_LEGACY_PTYS and CONFIG_UNIX98_PTYS are enabled, the call to tty_register_driver() in unix98_pty_init() will fail. 2. Different tty ports may be used for different tasks, which may require separate core binding control via workqueues. In this case, the workqueue created by default in the tty driver is unnecessary. Enabling this flag prevents the creation of this redundant workqueue. After applying this patch, we can set the related UART TTY flip buffer workqueue by sysfs. We set the cpumask to CPU cores associated with the IMU tasks, and set the nice to -20. Testing has shown significant improvement in the previously described issue, with almost no stuttering occurring anymore. Signed-off-by: Xin Zhao <jackzxcui1989@163.com> Reviewed-by: Jiri Slaby <jirislaby@kernel.org> Link: https://patch.msgid.link/20251223034836.2625547-1-jackzxcui1989@163.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-01-23serial: 8250_pci: Remove custom deprecated baud setting routineAndy Shevchenko1-51/+40
As comments mentioned this is old (and actually deprecated) interface to set custom baud rates. This interface has limitations as it only allows to set a single opaque value called "custom_divisor". If the HW needs more complex settings (like fractional divisor) it must somehow encode this. This is horrid interface that is very driver specific and not flexible. Meanwhile Linux has established way to set free baud rate settings via BOTHER [1]. With all this being said, remove deprecated interface for good. Link: https://stackoverflow.com/questions/12646324/how-can-i-set-a-custom-baud-rate-on-linux [1] Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Link: https://patch.msgid.link/20260122102349.2395423-3-andriy.shevchenko@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-01-23serial: 8250_omap: Remove custom deprecated baud setting routineAndy Shevchenko1-16/+0
As comments mentioned this is old (and actually deprecated) interface to set custom baud rates. This interface has limitations as it only allows to set a single opaque value called "custom_divisor". If the HW needs more complex settings (like fractional divisor) it must somehow encode this. This is horrid interface that is very driver specific and not flexible. Meanwhile Linux has established way to set free baud rate settings via BOTHER [1]. With all this being said, remove deprecated interface for good. Link: https://stackoverflow.com/questions/12646324/how-can-i-set-a-custom-baud-rate-on-linux [1] Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Link: https://patch.msgid.link/20260122102349.2395423-2-andriy.shevchenko@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
generated by cgit v1.2.3 (git 2.39.0) at 2026-06-11 07:49:10 +0300