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7 daysserial: sprd: Return -EPROBE_DEFER when uart clock is not readyWenhua Lin1-0/+6
[ Upstream commit 29e8a0c587e328ed458380a45d6028adf64d7487 ] In sprd_clk_init(), when devm_clk_get() returns -EPROBE_DEFER for either uart or source clock, we should propagate the error instead of just warning and continuing with NULL clocks. Currently the driver only emits a warning when clock acquisition fails and proceeds with NULL clock pointers. This can lead to issues later when the clocks are actually needed. More importantly, when the clock provider is not ready yet and returns -EPROBE_DEFER, we should return this error to allow deferred probing. This change adds explicit checks for -EPROBE_DEFER after both: 1. devm_clk_get(uport->dev, uart) 2. devm_clk_get(uport->dev, source) When -EPROBE_DEFER is encountered, the function now returns -EPROBE_DEFER to let the driver framework retry probing later when the clock dependencies are resolved. Signed-off-by: Wenhua Lin <Wenhua.Lin@unisoc.com> Link: https://patch.msgid.link/20251022030840.956589-1-Wenhua.Lin@unisoc.com Reviewed-by: Cixi Geng <cixi.geng@linux.dev> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
7 daysserial: add support of CPCI cardsMagne Bruno1-0/+37
commit 0e5a99e0e5f50353b86939ff6e424800d769c818 upstream. Addi-Data GmbH is manufacturing multi-serial ports cards supporting CompactPCI (known as CPCI). Those cards are identified with different DeviceIds. Those cards integrating standard UARTs work the same way as PCI/PCIe models already supported in the serial driver. Signed-off-by: Magne Bruno <magne.bruno@addi-data.com> Link: https://patch.msgid.link/20251110162456.341029-1-magne.bruno@addi-data.com Cc: stable <stable@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-12-07serial: amba-pl011: prefer dma_mapping_error() over explicit address checkingMiaoqian Lin1-1/+1
commit eb4917f557d43c7a1c805dd73ffcdfddb2aba39a upstream. Check for returned DMA addresses using specialized dma_mapping_error() helper which is generally recommended for this purpose by Documentation/core-api/dma-api.rst: "In some circumstances dma_map_single(), ... will fail to create a mapping. A driver can check for these errors by testing the returned DMA address with dma_mapping_error()." Found via static analysis and this is similar to commit fa0308134d26 ("ALSA: memalloc: prefer dma_mapping_error() over explicit address checking") Fixes: 58ac1b379979 ("ARM: PL011: Fix DMA support") Cc: stable <stable@kernel.org> Signed-off-by: Miaoqian Lin <linmq006@gmail.com> Reviewed-by: Gregory CLEMENT <gregory.clement@bootlin.com> Link: https://patch.msgid.link/20251027092053.87937-1-linmq006@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-12-07serial: 8250_dw: handle reset control deassert errorArtem Shimko1-1/+3
[ Upstream commit daeb4037adf7d3349b4a1fb792f4bc9824686a4b ] Check the return value of reset_control_deassert() in the probe function to prevent continuing probe when reset deassertion fails. Previously, reset_control_deassert() was called without checking its return value, which could lead to probe continuing even when the device reset wasn't properly deasserted. The fix checks the return value and returns an error with dev_err_probe() if reset deassertion fails, providing better error handling and diagnostics. Fixes: acbdad8dd1ab ("serial: 8250_dw: simplify optional reset handling") Cc: stable <stable@kernel.org> Signed-off-by: Artem Shimko <a.shimko.dev@gmail.com> Link: https://patch.msgid.link/20251019095131.252848-1-a.shimko.dev@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-12-07serial: 8250_dw: Use devm_add_action_or_reset()Andy Shevchenko1-32/+31
[ Upstream commit 295b09128d12fb1a7a67f771cc0ae0df869eafaf ] Slightly simplify ->probe() and drop a few goto labels by using devm_add_action_or_reset() for clock and reset cleanup. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Link: https://lore.kernel.org/r/20220509172129.37770-1-andriy.shevchenko@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Stable-dep-of: daeb4037adf7 ("serial: 8250_dw: handle reset control deassert error") Signed-off-by: Sasha Levin <sashal@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-10-29serial: 8250_exar: add support for Advantech 2 port card with Device ID 0x0018Florian Eckert1-0/+11
commit e7cbce761fe3fcbcb49bcf30d4f8ca5e1a9ee2a0 upstream. The Advantech 2-port serial card with PCI vendor=0x13fe and device=0x0018 has a 'XR17V35X' chip installed on the circuit board. Therefore, this driver can be used instead of theu outdated out-of-tree driver from the manufacturer. Signed-off-by: Florian Eckert <fe@dev.tdt.de> Cc: stable <stable@kernel.org> Link: https://patch.msgid.link/20250924134115.2667650-1-fe@dev.tdt.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-10-29serial: max310x: Add error checking in probe()Dan Carpenter1-0/+2
[ Upstream commit 672a37ba8af1f2ebcedeb94aea2cdd047f805f30 ] Check if devm_i2c_new_dummy_device() fails. Fixes: 2e1f2d9a9bdb ("serial: max310x: implement I2C support") Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org> Link: https://lore.kernel.org/r/aJTMPZiKqeXSE-KM@stanley.mountain Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-10-29serial: stm32: allow selecting console when the driver is moduleRaphael Gallais-Pou1-1/+1
commit cc4d900d0d6d8dd5c41832a93ff3cfa629a78f9a upstream. Console can be enabled on the UART compile as module. Change dependency to allow console mode when the driver is built as module. Fixes: 48a6092fb41fa ("serial: stm32-usart: Add STM32 USART Driver") Cc: stable@vger.kernel.org Signed-off-by: Raphael Gallais-Pou <raphael.gallais-pou@foss.st.com> Link: https://lore.kernel.org/r/20250822141923.61133-1-raphael.gallais-pou@foss.st.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-10-02serial: sc16is7xx: fix bug in flow control levels initHugo Villeneuve1-12/+2
[ Upstream commit 535fd4c98452c87537a40610abba45daf5761ec6 ] When trying to set MCR[2], XON1 is incorrectly accessed instead. And when writing to the TCR register to configure flow control levels, we are incorrectly writing to the MSR register. The default value of $00 is then used for TCR, which means that selectable trigger levels in FCR are used in place of TCR. TCR/TLR access requires EFR[4] (enable enhanced functions) and MCR[2] to be set. EFR[4] is already set in probe(). MCR access requires LCR[7] to be zero. Since LCR is set to $BF when trying to set MCR[2], XON1 is incorrectly accessed instead because MCR shares the same address space as XON1. Since MCR[2] is unmodified and still zero, when writing to TCR we are in fact writing to MSR because TCR/TLR registers share the same address space as MSR/SPR. Fix by first removing useless reconfiguration of EFR[4] (enable enhanced functions), as it is already enabled in sc16is7xx_probe() since commit 43c51bb573aa ("sc16is7xx: make sure device is in suspend once probed"). Now LCR is $00, which means that MCR access is enabled. Also remove regcache_cache_bypass() calls since we no longer access the enhanced registers set, and TCR is already declared as volatile (in fact by declaring MSR as volatile, which shares the same address). Finally disable access to TCR/TLR registers after modifying them by clearing MCR[2]. Note: the comment about "... and internal clock div" is wrong and can be ignored/removed as access to internal clock div registers (DLL/DLH) is permitted only when LCR[7] is logic 1, not when enhanced features is enabled. And DLL/DLH access is not needed in sc16is7xx_startup(). Fixes: dfeae619d781 ("serial: sc16is7xx") Cc: stable@vger.kernel.org Signed-off-by: Hugo Villeneuve <hvilleneuve@dimonoff.com> Link: https://lore.kernel.org/r/20250731124451.1108864-1-hugo@hugovil.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> [ changed regmap variable from one->regmap to s->regmap ] Signed-off-by: Sasha Levin <sashal@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-08-28serial: 8250: fix panic due to PSLVERRYunhui Cui1-2/+1
commit 7f8fdd4dbffc05982b96caf586f77a014b2a9353 upstream. When the PSLVERR_RESP_EN parameter is set to 1, the device generates an error response if an attempt is made to read an empty RBR (Receive Buffer Register) while the FIFO is enabled. In serial8250_do_startup(), calling serial_port_out(port, UART_LCR, UART_LCR_WLEN8) triggers dw8250_check_lcr(), which invokes dw8250_force_idle() and serial8250_clear_and_reinit_fifos(). The latter function enables the FIFO via serial_out(p, UART_FCR, p->fcr). Execution proceeds to the serial_port_in(port, UART_RX). This satisfies the PSLVERR trigger condition. When another CPU (e.g., using printk()) is accessing the UART (UART is busy), the current CPU fails the check (value & ~UART_LCR_SPAR) == (lcr & ~UART_LCR_SPAR) in dw8250_check_lcr(), causing it to enter dw8250_force_idle(). Put serial_port_out(port, UART_LCR, UART_LCR_WLEN8) under the port->lock to fix this issue. Panic backtrace: [ 0.442336] Oops - unknown exception [#1] [ 0.442343] epc : dw8250_serial_in32+0x1e/0x4a [ 0.442351] ra : serial8250_do_startup+0x2c8/0x88e ... [ 0.442416] console_on_rootfs+0x26/0x70 Fixes: c49436b657d0 ("serial: 8250_dw: Improve unwritable LCR workaround") Link: https://lore.kernel.org/all/84cydt5peu.fsf@jogness.linutronix.de/T/ Signed-off-by: Yunhui Cui <cuiyunhui@bytedance.com> Reviewed-by: John Ogness <john.ogness@linutronix.de> Cc: stable <stable@kernel.org> Link: https://lore.kernel.org/r/20250723023322.464-2-cuiyunhui@bytedance.com [ Applied fix to serial8250_do_startup() instead of serial8250_initialize() ] Signed-off-by: Sasha Levin <sashal@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-08-28pch_uart: Fix dma_sync_sg_for_device() nents valueThomas Fourier1-1/+1
commit 6c0e9f05c9d7875995b0e92ace71be947f280bbd upstream. The dma_sync_sg_for_device() functions should be called with the same nents as the dma_map_sg(), not the value the map function returned according to the documentation in Documentation/core-api/dma-api.rst:450: With the sync_sg API, all the parameters must be the same as those passed into the sg mapping API. Fixes: da3564ee027e ("pch_uart: add multi-scatter processing") Cc: stable <stable@kernel.org> Signed-off-by: Thomas Fourier <fourier.thomas@gmail.com> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Link: https://lore.kernel.org/r/20250701113452.18590-2-fourier.thomas@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-06-27serial: sh-sci: Increment the runtime usage counter for the earlycon deviceClaudiu Beznea1-0/+16
commit 651dee03696e1dfde6d9a7e8664bbdcd9a10ea7f upstream. In the sh-sci driver, serial ports are mapped to the sci_ports[] array, with earlycon mapped at index zero. The uart_add_one_port() function eventually calls __device_attach(), which, in turn, calls pm_request_idle(). The identified code path is as follows: uart_add_one_port() -> serial_ctrl_register_port() -> serial_core_register_port() -> serial_core_port_device_add() -> serial_base_port_add() -> device_add() -> bus_probe_device() -> device_initial_probe() -> __device_attach() -> // ... if (dev->p->dead) { // ... } else if (dev->driver) { // ... } else { // ... pm_request_idle(dev); // ... } The earlycon device clocks are enabled by the bootloader. However, the pm_request_idle() call in __device_attach() disables the SCI port clocks while earlycon is still active. The earlycon write function, serial_console_write(), calls sci_poll_put_char() via serial_console_putchar(). If the SCI port clocks are disabled, writing to earlycon may sometimes cause the SR.TDFE bit to remain unset indefinitely, causing the while loop in sci_poll_put_char() to never exit. On single-core SoCs, this can result in the system being blocked during boot when this issue occurs. To resolve this, increment the runtime PM usage counter for the earlycon SCI device before registering the UART port. Fixes: 0b0cced19ab1 ("serial: sh-sci: Add CONFIG_SERIAL_EARLYCON support") Cc: stable@vger.kernel.org Signed-off-by: Claudiu Beznea <claudiu.beznea.uj@bp.renesas.com> Link: https://lore.kernel.org/r/20250116182249.3828577-6-claudiu.beznea.uj@bp.renesas.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-06-27serial: sh-sci: Clean sci_ports[0] after at earlycon exitClaudiu Beznea1-2/+30
commit 5f1017069933489add0c08659673443c9905659e upstream. The early_console_setup() function initializes sci_ports[0].port with an object of type struct uart_port obtained from the struct earlycon_device passed as an argument to early_console_setup(). Later, during serial port probing, the serial port used as earlycon (e.g., port A) might be remapped to a different position in the sci_ports[] array, and a different serial port (e.g., port B) might be assigned to slot 0. For example: sci_ports[0] = port B sci_ports[X] = port A In this scenario, the new port mapped at index zero (port B) retains the data associated with the earlycon configuration. Consequently, after the Linux boot process, any access to the serial port now mapped to sci_ports[0] (port B) will block the original earlycon port (port A). To address this, introduce an early_console_exit() function to clean up sci_ports[0] when earlycon is exited. To prevent the cleanup of sci_ports[0] while the serial device is still being used by earlycon, introduce the struct sci_port::probing flag and account for it in early_console_exit(). Fixes: 0b0cced19ab1 ("serial: sh-sci: Add CONFIG_SERIAL_EARLYCON support") Cc: stable@vger.kernel.org Signed-off-by: Claudiu Beznea <claudiu.beznea.uj@bp.renesas.com> Link: https://lore.kernel.org/r/20250116182249.3828577-5-claudiu.beznea.uj@bp.renesas.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Claudiu Beznea <claudiu.beznea.uj@bp.renesas.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-06-27serial: sh-sci: Move runtime PM enable to sci_probe_single()Claudiu Beznea1-18/+6
commit 239f11209e5f282e16f5241b99256e25dd0614b6 upstream. Relocate the runtime PM enable operation to sci_probe_single(). This change prepares the codebase for upcoming fixes. While at it, replace the existing logic with a direct call to devm_pm_runtime_enable() and remove sci_cleanup_single(). The devm_pm_runtime_enable() function automatically handles disabling runtime PM during driver removal. Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be> Signed-off-by: Claudiu Beznea <claudiu.beznea.uj@bp.renesas.com> Link: https://lore.kernel.org/r/20250116182249.3828577-3-claudiu.beznea.uj@bp.renesas.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Claudiu Beznea <claudiu.beznea.uj@bp.renesas.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-06-27serial: sh-sci: Check if TX data was written to device in .tx_empty()Claudiu Beznea1-0/+29
commit 7cc0e0a43a91052477c2921f924a37d9c3891f0c upstream. On the Renesas RZ/G3S, when doing suspend to RAM, the uart_suspend_port() is called. The uart_suspend_port() calls 3 times the struct uart_port::ops::tx_empty() before shutting down the port. According to the documentation, the struct uart_port::ops::tx_empty() API tests whether the transmitter FIFO and shifter for the port is empty. The Renesas RZ/G3S SCIFA IP reports the number of data units stored in the transmit FIFO through the FDR (FIFO Data Count Register). The data units in the FIFOs are written in the shift register and transmitted from there. The TEND bit in the Serial Status Register reports if the data was transmitted from the shift register. In the previous code, in the tx_empty() API implemented by the sh-sci driver, it is considered that the TX is empty if the hardware reports the TEND bit set and the number of data units in the FIFO is zero. According to the HW manual, the TEND bit has the following meaning: 0: Transmission is in the waiting state or in progress. 1: Transmission is completed. It has been noticed that when opening the serial device w/o using it and then switch to a power saving mode, the tx_empty() call in the uart_port_suspend() function fails, leading to the "Unable to drain transmitter" message being printed on the console. This is because the TEND=0 if nothing has been transmitted and the FIFOs are empty. As the TEND=0 has double meaning (waiting state, in progress) we can't determined the scenario described above. Add a software workaround for this. This sets a variable if any data has been sent on the serial console (when using PIO) or if the DMA callback has been called (meaning something has been transmitted). In the tx_empty() API the status of the DMA transaction is also checked and if it is completed or in progress the code falls back in checking the hardware registers instead of relying on the software variable. Fixes: 73a19e4c0301 ("serial: sh-sci: Add DMA support.") Cc: stable@vger.kernel.org Signed-off-by: Claudiu Beznea <claudiu.beznea.uj@bp.renesas.com> Link: https://lore.kernel.org/r/20241125115856.513642-1-claudiu.beznea.uj@bp.renesas.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> [claudiu.beznea: fixed conflict by: - keeping serial_port_out() instead of sci_port_out() in sci_transmit_chars() - keeping !uart_circ_empty(xmit) condition in sci_dma_tx_complete(), after s->tx_occurred = true; assignement] Signed-off-by: Claudiu Beznea <claudiu.beznea.uj@bp.renesas.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-06-27serial: Fix potential null-ptr-deref in mlb_usio_probe()Henry Martin1-1/+4
[ Upstream commit 86bcae88c9209e334b2f8c252f4cc66beb261886 ] devm_ioremap() can return NULL on error. Currently, mlb_usio_probe() does not check for this case, which could result in a NULL pointer dereference. Add NULL check after devm_ioremap() to prevent this issue. Fixes: ba44dc043004 ("serial: Add Milbeaut serial control") Signed-off-by: Henry Martin <bsdhenrymartin@gmail.com> Link: https://lore.kernel.org/r/20250403070339.64990-1-bsdhenrymartin@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-05-02serial: sifive: lock port in startup()/shutdown() callbacksRyo Takakura1-0/+6
commit e1ca3ff28ab1e2c1e70713ef3fa7943c725742c3 upstream. startup()/shutdown() callbacks access SIFIVE_SERIAL_IE_OFFS. The register is also accessed from write() callback. If console were printing and startup()/shutdown() callback gets called, its access to the register could be overwritten. Add port->lock to startup()/shutdown() callbacks to make sure their access to SIFIVE_SERIAL_IE_OFFS is synchronized against write() callback. Fixes: 45c054d0815b ("tty: serial: add driver for the SiFive UART") Signed-off-by: Ryo Takakura <ryotkkr98@gmail.com> Reviewed-by: Petr Mladek <pmladek@suse.com> Cc: stable@vger.kernel.org Reviewed-by: John Ogness <john.ogness@linutronix.de> Rule: add Link: https://lore.kernel.org/stable/20250330003522.386632-1-ryotkkr98%40gmail.com Link: https://lore.kernel.org/r/20250412001847.183221-1-ryotkkr98@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-04-10tty: serial: fsl_lpuart: disable transmitter before changing RS485 related ↵Sherry Sun1-0/+17
registers [ Upstream commit f5cb528d6441eb860250a2f085773aac4f44085e ] According to the LPUART reference manual, TXRTSE and TXRTSPOL of MODIR register only can be changed when the transmitter is disabled. So disable the transmitter before changing RS485 related registers and re-enable it after the change is done. Fixes: 67b01837861c ("tty: serial: lpuart: Add RS485 support for 32-bit uart flavour") Cc: stable <stable@kernel.org> Signed-off-by: Sherry Sun <sherry.sun@nxp.com> Reviewed-by: Frank Li <Frank.Li@nxp.com> Link: https://lore.kernel.org/r/20250312022503.1342990-1-sherry.sun@nxp.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-04-10tty: serial: fsl_lpuart: use UARTMODIR register bits for lpuart32 platformSherry Sun1-4/+4
[ Upstream commit d57d56e4dddfb5c92cd81abf8922055bf0fb85a4 ] For lpuart32 platforms, UARTMODIR register is used instead of UARTMODEM. So here should configure the corresponding UARTMODIR register bits to avoid confusion. Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Signed-off-by: Sherry Sun <sherry.sun@nxp.com> Link: https://lore.kernel.org/r/20230414022111.20896-1-sherry.sun@nxp.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Stable-dep-of: f5cb528d6441 ("tty: serial: fsl_lpuart: disable transmitter before changing RS485 related registers") Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-04-10serial: 8250_dma: terminate correct DMA in tx_dma_flush()John Keeping1-1/+1
commit a26503092c75abba70a0be2aa01145ecf90c2a22 upstream. When flushing transmit side DMA, it is the transmit channel that should be terminated, not the receive channel. Fixes: 9e512eaaf8f40 ("serial: 8250: Fix fifo underflow on flush") Cc: stable <stable@kernel.org> Reported-by: Wentao Guan <guanwentao@uniontech.com> Signed-off-by: John Keeping <jkeeping@inmusicbrands.com> Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Link: https://lore.kernel.org/r/20250224121831.1429323-1-jkeeping@inmusicbrands.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-04-10tty: serial: 8250: Add some more device IDsCameron Williams1-0/+16
commit be6a23650908e2f827f2e7839a3fbae41ccb5b63 upstream. These card IDs got missed the first time around. Cc: stable <stable@kernel.org> Signed-off-by: Cameron Williams <cang1@live.co.uk> Link: https://lore.kernel.org/r/DB7PR02MB380295BCC879CCF91315AC38C4C12@DB7PR02MB3802.eurprd02.prod.outlook.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-03-13serial: 8250_pci: add support for ASIX AX99100Jiaqing Zhao1-0/+10
commit 0b32216557ce3b2a468d1282d99b428bf72ff532 upstream. Each of the 4 PCI functions on ASIX AX99100 PCIe to Multi I/O Controller can be configured as a single-port serial port controller. The subvendor id is 0x1000 when configured as serial port and MSI interrupts are supported. Signed-off-by: Jiaqing Zhao <jiaqing.zhao@linux.intel.com> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Link: https://lore.kernel.org/r/20230724083933.3173513-4-jiaqing.zhao@linux.intel.com Signed-off-by: Tomita Moeko <tomitamoeko@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-03-13serial: 8250: Fix fifo underflow on flushJohn Keeping3-0/+27
commit 9e512eaaf8f4008c44ede3dfc0fbc9d9c5118583 upstream. When flushing the serial port's buffer, uart_flush_buffer() calls kfifo_reset() but if there is an outstanding DMA transfer then the completion function will consume data from the kfifo via uart_xmit_advance(), underflowing and leading to ongoing DMA as the driver tries to transmit another 2^32 bytes. This is readily reproduced with serial-generic and amidi sending even short messages as closing the device on exit will wait for the fifo to drain and in the underflow case amidi hangs for 30 seconds on exit in tty_wait_until_sent(). A trace of that gives: kworker/1:1-84 [001] 51.769423: bprint: serial8250_tx_dma: tx_size=3 fifo_len=3 amidi-763 [001] 51.769460: bprint: uart_flush_buffer: resetting fifo irq/21-fe530000-76 [000] 51.769474: bprint: __dma_tx_complete: tx_size=3 irq/21-fe530000-76 [000] 51.769479: bprint: serial8250_tx_dma: tx_size=4096 fifo_len=4294967293 irq/21-fe530000-76 [000] 51.781295: bprint: __dma_tx_complete: tx_size=4096 irq/21-fe530000-76 [000] 51.781301: bprint: serial8250_tx_dma: tx_size=4096 fifo_len=4294963197 irq/21-fe530000-76 [000] 51.793131: bprint: __dma_tx_complete: tx_size=4096 irq/21-fe530000-76 [000] 51.793135: bprint: serial8250_tx_dma: tx_size=4096 fifo_len=4294959101 irq/21-fe530000-76 [000] 51.804949: bprint: __dma_tx_complete: tx_size=4096 Since the port lock is held in when the kfifo is reset in uart_flush_buffer() and in __dma_tx_complete(), adding a flush_buffer hook to adjust the outstanding DMA byte count is sufficient to avoid the kfifo underflow. Fixes: 9ee4b83e51f74 ("serial: 8250: Add support for dmaengine") Cc: stable <stable@kernel.org> Signed-off-by: John Keeping <jkeeping@inmusicbrands.com> Link: https://lore.kernel.org/r/20250208124148.1189191-1-jkeeping@inmusicbrands.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-03-13serial: sh-sci: Do not probe the serial port if its slot in sci_ports[] is ↵Claudiu Beznea1-0/+23
in use commit 9f7dea875cc7f9c1a56a5c688290634a59cd1420 upstream. In the sh-sci driver, sci_ports[0] is used by earlycon. If the earlycon is still active when sci_probe() is called and the new serial port is supposed to map to sci_ports[0], return -EBUSY to prevent breaking the earlycon. This situation should occurs in debug scenarios, and users should be aware of the potential conflict. Fixes: 0b0cced19ab1 ("serial: sh-sci: Add CONFIG_SERIAL_EARLYCON support") Cc: stable@vger.kernel.org Signed-off-by: Claudiu Beznea <claudiu.beznea.uj@bp.renesas.com> Link: https://lore.kernel.org/r/20250116182249.3828577-4-claudiu.beznea.uj@bp.renesas.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-03-13serial: sh-sci: Drop __initdata macro for port_cfgClaudiu Beznea1-1/+1
commit eaeee4225dba30bef4d424bdf134a07b7f423e8b upstream. The port_cfg object is used by serial_console_write(), which serves as the write function for the earlycon device. Marking port_cfg as __initdata causes it to be freed after kernel initialization, resulting in earlycon becoming unavailable thereafter. Remove the __initdata macro from port_cfg to resolve this issue. Fixes: 0b0cced19ab1 ("serial: sh-sci: Add CONFIG_SERIAL_EARLYCON support") Cc: stable@vger.kernel.org Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be> Signed-off-by: Claudiu Beznea <claudiu.beznea.uj@bp.renesas.com> Fixes: 0b0cced19ab15c9e ("serial: sh-sci: Add CONFIG_SERIAL_EARLYCON support") Link: https://lore.kernel.org/r/20250116182249.3828577-2-claudiu.beznea.uj@bp.renesas.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-12-14serial: 8250: omap: Move pm_runtime_get_syncBin Liu1-2/+2
commit bcc7ba668818dcadd2f1db66b39ed860a63ecf97 upstream. Currently in omap_8250_shutdown, the dma->rx_running flag is set to zero in omap_8250_rx_dma_flush. Next pm_runtime_get_sync is called, which is a runtime resume call stack which can re-set the flag. When the call omap_8250_shutdown returns, the flag is expected to be UN-SET, but this is not the case. This is causing issues the next time UART is re-opened and omap_8250_rx_dma is called. Fix by moving pm_runtime_get_sync before the omap_8250_rx_dma_flush. cc: stable@vger.kernel.org Fixes: 0e31c8d173ab ("tty: serial: 8250_omap: add custom DMA-RX callback") Signed-off-by: Bin Liu <b-liu@ti.com> [Judith: Add commit message] Signed-off-by: Judith Mendez <jm@ti.com> Reviewed-by: Kevin Hilman <khilman@baylibre.com> Tested-by: Kevin Hilman <khilman@baylibre.com> Link: https://lore.kernel.org/r/20241031172315.453750-1-jm@ti.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-12-14Revert "serial: sh-sci: Clean sci_ports[0] after at earlycon exit"Greg Kroah-Hartman1-28/+0
commit 718632467d88e98816fa01ab12681ef1c2aa56f8 upstream. This reverts commit 3791ea69a4858b81e0277f695ca40f5aae40f312. It was reported to cause boot-time issues, so revert it for now. Reported-by: Geert Uytterhoeven <geert@linux-m68k.org> Fixes: 3791ea69a485 ("serial: sh-sci: Clean sci_ports[0] after at earlycon exit") Cc: stable <stable@kernel.org> Cc: Claudiu Beznea <claudiu.beznea.uj@bp.renesas.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-12-14serial: sh-sci: Clean sci_ports[0] after at earlycon exitClaudiu Beznea1-0/+28
commit 3791ea69a4858b81e0277f695ca40f5aae40f312 upstream. The early_console_setup() function initializes the sci_ports[0].port with an object of type struct uart_port obtained from the object of type struct earlycon_device received as argument by the early_console_setup(). It may happen that later, when the rest of the serial ports are probed, the serial port that was used as earlycon (e.g., port A) to be mapped to a different position in sci_ports[] and the slot 0 to be used by a different serial port (e.g., port B), as follows: sci_ports[0] = port A sci_ports[X] = port B In this case, the new port mapped at index zero will have associated data that was used for earlycon. In case this happens, after Linux boot, any access to the serial port that maps on sci_ports[0] (port A) will block the serial port that was used as earlycon (port B). To fix this, add early_console_exit() that clean the sci_ports[0] at earlycon exit time. Fixes: 0b0cced19ab1 ("serial: sh-sci: Add CONFIG_SERIAL_EARLYCON support") Cc: stable@vger.kernel.org Signed-off-by: Claudiu Beznea <claudiu.beznea.uj@bp.renesas.com> Link: https://lore.kernel.org/r/20241106120118.1719888-4-claudiu.beznea.uj@bp.renesas.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-11-08serial: protect uart_port_dtr_rts() in uart_shutdown() tooJiri Slaby (SUSE)1-7/+9
[ Upstream commit 602babaa84d627923713acaf5f7e9a4369e77473 ] Commit af224ca2df29 (serial: core: Prevent unsafe uart port access, part 3) added few uport == NULL checks. It added one to uart_shutdown(), so the commit assumes, uport can be NULL in there. But right after that protection, there is an unprotected "uart_port_dtr_rts(uport, false);" call. That is invoked only if HUPCL is set, so I assume that is the reason why we do not see lots of these reports. Or it cannot be NULL at this point at all for some reason :P. Until the above is investigated, stay on the safe side and move this dereference to the if too. I got this inconsistency from Coverity under CID 1585130. Thanks. Signed-off-by: Jiri Slaby (SUSE) <jirislaby@kernel.org> Cc: Peter Hurley <peter@hurleysoftware.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Link: https://lore.kernel.org/r/20240805102046.307511-3-jirislaby@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> [Adapted over commit 5701cb8bf50e ("tty: Call ->dtr_rts() parameter active consistently") not in the tree] Signed-off-by: Tomas Krcka <krckatom@amazon.de> Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-10-17tty: rp2: Fix reset with non forgiving PCIe host bridgesFlorian Fainelli1-1/+1
commit f16dd10ba342c429b1e36ada545fb36d4d1f0e63 upstream. The write to RP2_GLOBAL_CMD followed by an immediate read of RP2_GLOBAL_CMD in rp2_reset_asic() is intented to flush out the write, however by then the device is already in reset and cannot respond to a memory cycle access. On platforms such as the Raspberry Pi 4 and others using the pcie-brcmstb.c driver, any memory access to a device that cannot respond is met with a fatal system error, rather than being substituted with all 1s as is usually the case on PC platforms. Swapping the delay and the read ensures that the device has finished resetting before we attempt to read from it. Fixes: 7d9f49afa451 ("serial: rp2: New driver for Comtrol RocketPort 2 cards") Cc: stable <stable@kernel.org> Suggested-by: Jim Quinlan <james.quinlan@broadcom.com> Signed-off-by: Florian Fainelli <florian.fainelli@broadcom.com> Link: https://lore.kernel.org/r/20240906225435.707837-1-florian.fainelli@broadcom.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-08-19serial: core: check uartclk for zero to avoid divide by zeroGeorge Kennedy1-0/+8
commit 6eabce6608d6f3440f4c03aa3d3ef50a47a3d193 upstream. Calling ioctl TIOCSSERIAL with an invalid baud_base can result in uartclk being zero, which will result in a divide by zero error in uart_get_divisor(). The check for uartclk being zero in uart_set_info() needs to be done before other settings are made as subsequent calls to ioctl TIOCSSERIAL for the same port would be impacted if the uartclk check was done where uartclk gets set. Oops: divide error: 0000 PREEMPT SMP KASAN PTI RIP: 0010:uart_get_divisor (drivers/tty/serial/serial_core.c:580) Call Trace: <TASK> serial8250_get_divisor (drivers/tty/serial/8250/8250_port.c:2576 drivers/tty/serial/8250/8250_port.c:2589) serial8250_do_set_termios (drivers/tty/serial/8250/8250_port.c:502 drivers/tty/serial/8250/8250_port.c:2741) serial8250_set_termios (drivers/tty/serial/8250/8250_port.c:2862) uart_change_line_settings (./include/linux/spinlock.h:376 ./include/linux/serial_core.h:608 drivers/tty/serial/serial_core.c:222) uart_port_startup (drivers/tty/serial/serial_core.c:342) uart_startup (drivers/tty/serial/serial_core.c:368) uart_set_info (drivers/tty/serial/serial_core.c:1034) uart_set_info_user (drivers/tty/serial/serial_core.c:1059) tty_set_serial (drivers/tty/tty_io.c:2637) tty_ioctl (drivers/tty/tty_io.c:2647 drivers/tty/tty_io.c:2791) __x64_sys_ioctl (fs/ioctl.c:52 fs/ioctl.c:907 fs/ioctl.c:893 fs/ioctl.c:893) do_syscall_64 (arch/x86/entry/common.c:52 (discriminator 1) arch/x86/entry/common.c:83 (discriminator 1)) entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130) Reported-by: syzkaller <syzkaller@googlegroups.com> Cc: stable@vger.kernel.org Signed-off-by: George Kennedy <george.kennedy@oracle.com> Rule: add Link: https://lore.kernel.org/stable/1721148848-9784-1-git-send-email-george.kennedy%40oracle.com Link: https://lore.kernel.org/r/1721219078-3209-1-git-send-email-george.kennedy@oracle.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-07-05serial: 8250_omap: Fix Errata i2310 with RX FIFO level checkUdit Kumar1-1/+2
commit c128a1b0523b685c8856ddc0ac0e1caef1fdeee5 upstream. Errata i2310[0] says, Erroneous timeout can be triggered, if this Erroneous interrupt is not cleared then it may leads to storm of interrupts. Commit 9d141c1e6157 ("serial: 8250_omap: Implementation of Errata i2310") which added the workaround but missed ensuring RX FIFO is really empty before applying the errata workaround as recommended in the errata text. Fix this by adding back check for UART_OMAP_RX_LVL to be 0 for workaround to take effect. [0] https://www.ti.com/lit/pdf/sprz536 page 23 Fixes: 9d141c1e6157 ("serial: 8250_omap: Implementation of Errata i2310") Cc: stable@vger.kernel.org Reported-by: Vignesh Raghavendra <vigneshr@ti.com> Closes: https://lore.kernel.org/all/e96d0c55-0b12-4cbf-9d23-48963543de49@ti.com/ Signed-off-by: Udit Kumar <u-kumar1@ti.com> Link: https://lore.kernel.org/r/20240625160725.2102194-1-u-kumar1@ti.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-07-05tty: mcf: MCF54418 has 10 UARTSJean-Michel Hautbois1-1/+1
commit 7c92a8bd53f24d50c8cf4aba53bb75505b382fed upstream. Most of the colfires have up to 5 UARTs but MCF54418 has up-to 10 ! Change the maximum value authorized. Signed-off-by: Jean-Michel Hautbois <jeanmichel.hautbois@yoseli.org> Cc: stable <stable@kernel.org> Fixes: 2545cf6e94b4 ("m68knommu: allow 4 coldfire serial ports") Link: https://lore.kernel.org/r/20240620-upstream-uart-v1-1-a9d0d95fb19e@yoseli.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-07-05serial: 8250_omap: Implementation of Errata i2310Udit Kumar1-5/+20
commit 9d141c1e615795eeb93cd35501ad144ee997a826 upstream. As per Errata i2310[0], Erroneous timeout can be triggered, if this Erroneous interrupt is not cleared then it may leads to storm of interrupts, therefore apply Errata i2310 solution. [0] https://www.ti.com/lit/pdf/sprz536 page 23 Fixes: b67e830d38fa ("serial: 8250: 8250_omap: Fix possible interrupt storm on K3 SoCs") Cc: stable@vger.kernel.org Signed-off-by: Udit Kumar <u-kumar1@ti.com> Link: https://lore.kernel.org/r/20240619105903.165434-1-u-kumar1@ti.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-07-05serial: exar: adding missing CTI and Exar PCI idsParker Newman1-0/+42
[ Upstream commit b86ae40ffcf5a16b9569b1016da4a08c4f352ca2 ] - Added Connect Tech and Exar IDs not already in pci_ids.h Signed-off-by: Parker Newman <pnewman@connecttech.com> Link: https://lore.kernel.org/r/7c3d8e795a864dd9b0a00353b722060dc27c4e09.1713270624.git.pnewman@connecttech.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-07-05serial: 8250_pxa: Configure tx_loadsz to match FIFO IRQ levelDoug Brown1-0/+1
commit 5208e7ced520a813b4f4774451fbac4e517e78b2 upstream. The FIFO is 64 bytes, but the FCR is configured to fire the TX interrupt when the FIFO is half empty (bit 3 = 0). Thus, we should only write 32 bytes when a TX interrupt occurs. This fixes a problem observed on the PXA168 that dropped a bunch of TX bytes during large transmissions. Fixes: ab28f51c77cd ("serial: rewrite pxa2xx-uart to use 8250_core") Signed-off-by: Doug Brown <doug@schmorgal.com> Link: https://lore.kernel.org/r/20240519191929.122202-1-doug@schmorgal.com Cc: stable <stable@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-07-05serial: sc16is7xx: fix bug in sc16is7xx_set_baud() when using prescalerHugo Villeneuve1-5/+18
[ Upstream commit 8492bd91aa055907c67ef04f2b56f6dadd1f44bf ] When using a high speed clock with a low baud rate, the 4x prescaler is automatically selected if required. In that case, sc16is7xx_set_baud() properly configures the chip registers, but returns an incorrect baud rate by not taking into account the prescaler value. This incorrect baud rate is then fed to uart_update_timeout(). For example, with an input clock of 80MHz, and a selected baud rate of 50, sc16is7xx_set_baud() will return 200 instead of 50. Fix this by first changing the prescaler variable to hold the selected prescaler value instead of the MCR bitfield. Then properly take into account the selected prescaler value in the return value computation. Also add better documentation about the divisor value computation. Fixes: dfeae619d781 ("serial: sc16is7xx") Cc: stable@vger.kernel.org Signed-off-by: Hugo Villeneuve <hvilleneuve@dimonoff.com> Reviewed-by: Jiri Slaby <jirislaby@kernel.org> Link: https://lore.kernel.org/r/20240430200431.4102923-1-hugo@hugovil.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-07-05serial: sc16is7xx: replace hardcoded divisor value with BIT() macroHugo Villeneuve1-1/+1
[ Upstream commit 2e57cefc4477659527f7adab1f87cdbf60ef1ae6 ] To better show why the limit is what it is, since we have only 16 bits for the divisor. Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com> Suggested-by: Andy Shevchenko <andy.shevchenko@gmail.com> Signed-off-by: Hugo Villeneuve <hvilleneuve@dimonoff.com> Link: https://lore.kernel.org/r/20231221231823.2327894-13-hugo@hugovil.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Stable-dep-of: 8492bd91aa05 ("serial: sc16is7xx: fix bug in sc16is7xx_set_baud() when using prescaler") Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-06-16serial: sh-sci: protect invalidating RXDMA on shutdownWolfram Sang1-0/+5
[ Upstream commit aae20f6e34cd0cbd67a1d0e5877561c40109a81b ] The to-be-fixed commit removed locking when invalidating the DMA RX descriptors on shutdown. It overlooked that there is still a rx_timer running which may still access the protected data. So, re-add the locking. Reported-by: Dirk Behme <dirk.behme@de.bosch.com> Closes: https://lore.kernel.org/r/ee6c9e16-9f29-450e-81da-4a8dceaa8fc7@de.bosch.com Fixes: 2c4ee23530ff ("serial: sh-sci: Postpone DMA release when falling back to PIO") Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com> Link: https://lore.kernel.org/r/20240506114016.30498-7-wsa+renesas@sang-engineering.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-06-16serial: sc16is7xx: add proper sched.h include for sched_set_fifo()Hugo Villeneuve1-1/+1
[ Upstream commit 2a8e4ab0c93fad30769479f86849e22d63cd0e12 ] Replace incorrect include with the proper one for sched_set_fifo() declaration. Fixes: 28d2f209cd16 ("sched,serial: Convert to sched_set_fifo()") Signed-off-by: Hugo Villeneuve <hvilleneuve@dimonoff.com> Link: https://lore.kernel.org/r/20240409154253.3043822-2-hugo@hugovil.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-06-16serial: max3100: Fix bitwise typesAndy Shevchenko1-1/+4
[ Upstream commit e60955dbecb97f080848a57524827e2db29c70fd ] Sparse is not happy about misuse of bitwise types: .../max3100.c:194:13: warning: incorrect type in assignment (different base types) .../max3100.c:194:13: expected unsigned short [addressable] [usertype] etx .../max3100.c:194:13: got restricted __be16 [usertype] .../max3100.c:202:15: warning: cast to restricted __be16 Fix this by choosing proper types for the respective variables. Fixes: 7831d56b0a35 ("tty: MAX3100") Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Link: https://lore.kernel.org/r/20240402195306.269276-4-andriy.shevchenko@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-06-16serial: max3100: Update uart_driver_registered on driver removalAndy Shevchenko1-1/+3
[ Upstream commit 712a1fcb38dc7cac6da63ee79a88708fbf9c45ec ] The removal of the last MAX3100 device triggers the removal of the driver. However, code doesn't update the respective global variable and after insmod — rmmod — insmod cycle the kernel oopses: max3100 spi-PRP0001:01: max3100_probe: adding port 0 BUG: kernel NULL pointer dereference, address: 0000000000000408 ... RIP: 0010:serial_core_register_port+0xa0/0x840 ... max3100_probe+0x1b6/0x280 [max3100] spi_probe+0x8d/0xb0 Update the actual state so next time UART driver will be registered again. Hugo also noticed, that the error path in the probe also affected by having the variable set, and not cleared. Instead of clearing it move the assignment after the successfull uart_register_driver() call. Fixes: 7831d56b0a35 ("tty: MAX3100") Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Reviewed-by: Hugo Villeneuve <hvilleneuve@dimonoff.com> Link: https://lore.kernel.org/r/20240402195306.269276-3-andriy.shevchenko@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-06-16serial: max3100: Lock port->lock when calling uart_handle_cts_change()Andy Shevchenko1-1/+12
[ Upstream commit 77ab53371a2066fdf9b895246505f5ef5a4b5d47 ] uart_handle_cts_change() has to be called with port lock taken, Since we run it in a separate work, the lock may not be taken at the time of running. Make sure that it's taken by explicitly doing that. Without it we got a splat: WARNING: CPU: 0 PID: 10 at drivers/tty/serial/serial_core.c:3491 uart_handle_cts_change+0xa6/0xb0 ... Workqueue: max3100-0 max3100_work [max3100] RIP: 0010:uart_handle_cts_change+0xa6/0xb0 ... max3100_handlerx+0xc5/0x110 [max3100] max3100_work+0x12a/0x340 [max3100] Fixes: 7831d56b0a35 ("tty: MAX3100") Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Link: https://lore.kernel.org/r/20240402195306.269276-2-andriy.shevchenko@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-05-25serial: kgdboc: Fix NMI-safety problems from keyboard reset codeDaniel Thompson1-1/+29
commit b2aba15ad6f908d1a620fd97f6af5620c3639742 upstream. Currently, when kdb is compiled with keyboard support, then we will use schedule_work() to provoke reset of the keyboard status. Unfortunately schedule_work() gets called from the kgdboc post-debug-exception handler. That risks deadlock since schedule_work() is not NMI-safe and, even on platforms where the NMI is not directly used for debugging, the debug trap can have NMI-like behaviour depending on where breakpoints are placed. Fix this by using the irq work system, which is NMI-safe, to defer the call to schedule_work() to a point when it is safe to call. Reported-by: Liuye <liu.yeC@h3c.com> Closes: https://lore.kernel.org/all/20240228025602.3087748-1-liu.yeC@h3c.com/ Cc: stable@vger.kernel.org Reviewed-by: Douglas Anderson <dianders@chromium.org> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Link: https://lore.kernel.org/r/20240424-kgdboc_fix_schedule_work-v2-1-50f5a490aec5@linaro.org Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-05-02serial: mxs-auart: add spinlock around changing cts stateEmil Kronborg1-2/+6
[ Upstream commit 54c4ec5f8c471b7c1137a1f769648549c423c026 ] The uart_handle_cts_change() function in serial_core expects the caller to hold uport->lock. For example, I have seen the below kernel splat, when the Bluetooth driver is loaded on an i.MX28 board. [ 85.119255] ------------[ cut here ]------------ [ 85.124413] WARNING: CPU: 0 PID: 27 at /drivers/tty/serial/serial_core.c:3453 uart_handle_cts_change+0xb4/0xec [ 85.134694] Modules linked in: hci_uart bluetooth ecdh_generic ecc wlcore_sdio configfs [ 85.143314] CPU: 0 PID: 27 Comm: kworker/u3:0 Not tainted 6.6.3-00021-gd62a2f068f92 #1 [ 85.151396] Hardware name: Freescale MXS (Device Tree) [ 85.156679] Workqueue: hci0 hci_power_on [bluetooth] (...) [ 85.191765] uart_handle_cts_change from mxs_auart_irq_handle+0x380/0x3f4 [ 85.198787] mxs_auart_irq_handle from __handle_irq_event_percpu+0x88/0x210 (...) Cc: stable@vger.kernel.org Fixes: 4d90bb147ef6 ("serial: core: Document and assert lock requirements for irq helpers") Reviewed-by: Frank Li <Frank.Li@nxp.com> Signed-off-by: Emil Kronborg <emil.kronborg@protonmail.com> Link: https://lore.kernel.org/r/20240320121530.11348-1-emil.kronborg@protonmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-05-02serial/pmac_zilog: Remove flawed mitigation for rx irq floodFinn Thain1-14/+0
commit 1be3226445362bfbf461c92a5bcdb1723f2e4907 upstream. The mitigation was intended to stop the irq completely. That may be better than a hard lock-up but it turns out that you get a crash anyway if you're using pmac_zilog as a serial console: ttyPZ0: pmz: rx irq flood ! BUG: spinlock recursion on CPU#0, swapper/0 That's because the pr_err() call in pmz_receive_chars() results in pmz_console_write() attempting to lock a spinlock already locked in pmz_interrupt(). With CONFIG_DEBUG_SPINLOCK=y, this produces a fatal BUG splat. The spinlock in question is the one in struct uart_port. Even when it's not fatal, the serial port rx function ceases to work. Also, the iteration limit doesn't play nicely with QEMU, as can be seen in the bug report linked below. A web search for other reports of the error message "pmz: rx irq flood" didn't produce anything. So I don't think this code is needed any more. Remove it. Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: Aneesh Kumar K.V <aneesh.kumar@kernel.org> Cc: Naveen N. Rao <naveen.n.rao@linux.ibm.com> Cc: Andy Shevchenko <andy.shevchenko@gmail.com> Cc: stable@kernel.org Cc: linux-m68k@lists.linux-m68k.org Link: https://github.com/vivier/qemu-m68k/issues/44 Link: https://lore.kernel.org/all/1078874617.9746.36.camel@gaston/ Acked-by: Michael Ellerman <mpe@ellerman.id.au> Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Cc: stable <stable@kernel.org> Signed-off-by: Finn Thain <fthain@linux-m68k.org> Link: https://lore.kernel.org/r/e853cf2c762f23101cd2ddec0cc0c2be0e72685f.1712568223.git.fthain@linux-m68k.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-04-13serial: sc16is7xx: convert from _raw_ to _noinc_ regmap functions for FIFOHugo Villeneuve1-6/+9
commit dbf4ab821804df071c8b566d9813083125e6d97b upstream. The SC16IS7XX IC supports a burst mode to access the FIFOs where the initial register address is sent ($00), followed by all the FIFO data without having to resend the register address each time. In this mode, the IC doesn't increment the register address for each R/W byte. The regmap_raw_read() and regmap_raw_write() are functions which can perform IO over multiple registers. They are currently used to read/write from/to the FIFO, and although they operate correctly in this burst mode on the SPI bus, they would corrupt the regmap cache if it was not disabled manually. The reason is that when the R/W size is more than 1 byte, these functions assume that the register address is incremented and handle the cache accordingly. Convert FIFO R/W functions to use the regmap _noinc_ versions in order to remove the manual cache control which was a workaround when using the _raw_ versions. FIFO registers are properly declared as volatile so cache will not be used/updated for FIFO accesses. Fixes: dfeae619d781 ("serial: sc16is7xx") Cc: <stable@vger.kernel.org> Signed-off-by: Hugo Villeneuve <hvilleneuve@dimonoff.com> Link: https://lore.kernel.org/r/20231211171353.2901416-6-hugo@hugovil.com Cc: Hugo Villeneuve <hvilleneuve@dimonoff.com> Signed-off-by: GONG, Ruiqi <gongruiqi1@huawei.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-04-13tty: serial: fsl_lpuart: avoid idle preamble pending if CTS is enabledSherry Sun1-2/+5
commit 74cb7e0355fae9641f825afa389d3fba3b617714 upstream. If the remote uart device is not connected or not enabled after booting up, the CTS line is high by default. At this time, if we enable the flow control when opening the device(for example, using “stty -F /dev/ttyLP4 crtscts” command), there will be a pending idle preamble(first writing 0 and then writing 1 to UARTCTRL_TE will queue an idle preamble) that cannot be sent out, resulting in the uart port fail to close(waiting for TX empty), so the user space stty will have to wait for a long time or forever. This is an LPUART IP bug(idle preamble has higher priority than CTS), here add a workaround patch to enable TX CTS after enabling UARTCTRL_TE, so that the idle preamble does not get stuck due to CTS is deasserted. Fixes: 380c966c093e ("tty: serial: fsl_lpuart: add 32-bit register interface support") Cc: stable <stable@kernel.org> Signed-off-by: Sherry Sun <sherry.sun@nxp.com> Reviewed-by: Alexander Sverdlin <alexander.sverdlin@siemens.com> Link: https://lore.kernel.org/r/20240305015706.1050769-1-sherry.sun@nxp.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-04-13serial: Lock console when calling into driver before registrationPeter Collingbourne2-6/+12
[ Upstream commit 801410b26a0e8b8a16f7915b2b55c9528b69ca87 ] During the handoff from earlycon to the real console driver, we have two separate drivers operating on the same device concurrently. In the case of the 8250 driver these concurrent accesses cause problems due to the driver's use of banked registers, controlled by LCR.DLAB. It is possible for the setup(), config_port(), pm() and set_mctrl() callbacks to set DLAB, which can cause the earlycon code that intends to access TX to instead access DLL, leading to missed output and corruption on the serial line due to unintended modifications to the baud rate. In particular, for setup() we have: univ8250_console_setup() -> serial8250_console_setup() -> uart_set_options() -> serial8250_set_termios() -> serial8250_do_set_termios() -> serial8250_do_set_divisor() For config_port() we have: serial8250_config_port() -> autoconfig() For pm() we have: serial8250_pm() -> serial8250_do_pm() -> serial8250_set_sleep() For set_mctrl() we have (for some devices): serial8250_set_mctrl() -> omap8250_set_mctrl() -> __omap8250_set_mctrl() To avoid such problems, let's make it so that the console is locked during pre-registration calls to these callbacks, which will prevent the earlycon driver from running concurrently. Remove the partial solution to this problem in the 8250 driver that locked the console only during autoconfig_irq(), as this would result in a deadlock with the new approach. The console continues to be locked during autoconfig_irq() because it can only be called through uart_configure_port(). Although this patch introduces more locking than strictly necessary (and in particular it also locks during the call to rs485_config() which is not affected by this issue as far as I can tell), it follows the principle that it is the responsibility of the generic console code to manage the earlycon handoff by ensuring that earlycon and real console driver code cannot run concurrently, and not the individual drivers. Signed-off-by: Peter Collingbourne <pcc@google.com> Reviewed-by: John Ogness <john.ogness@linutronix.de> Link: https://linux-review.googlesource.com/id/I7cf8124dcebf8618e6b2ee543fa5b25532de55d8 Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20240304214350.501253-1-pcc@google.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-04-13serial: max310x: fix NULL pointer dereference in I2C instantiationHugo Villeneuve1-2/+5
[ Upstream commit 0d27056c24efd3d63a03f3edfbcfc4827086b110 ] When trying to instantiate a max14830 device from userspace: echo max14830 0x60 > /sys/bus/i2c/devices/i2c-2/new_device we get the following error: Unable to handle kernel NULL pointer dereference at virtual address... ... Call trace: max310x_i2c_probe+0x48/0x170 [max310x] i2c_device_probe+0x150/0x2a0 ... Add check for validity of devtype to prevent the error, and abort probe with a meaningful error message. Fixes: 2e1f2d9a9bdb ("serial: max310x: implement I2C support") Cc: stable@vger.kernel.org Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com> Signed-off-by: Hugo Villeneuve <hvilleneuve@dimonoff.com> Link: https://lore.kernel.org/r/20240118152213.2644269-2-hugo@hugovil.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org>