kernel/linux.git/drivers/tty/serial/xilinx_uartps.c, branch v4.9.331

tty: xilinx_uartps: Fix the ignore_status

2022-10-26T11:15:42+00:00

[ Upstream commit b8a6c3b3d4654fba19881cc77da61eac29f57cae ] Currently the ignore_status is not considered in the isr. Add a check to add the ignore_status. Fixes: 61ec9016988f ("tty/serial: add support for Xilinx PS UART") Signed-off-by: Shubhrajyoti Datta Link: https://lore.kernel.org/r/20220729114748.18332-5-shubhrajyoti.datta@xilinx.com Signed-off-by: Greg Kroah-Hartman Signed-off-by: Sasha Levin

serial: xilinx_uartps: Fix race condition causing stuck TX

2021-11-26T10:48:37+00:00

[ Upstream commit 88b20f84f0fe47409342669caf3e58a3fc64c316 ] xilinx_uartps .start_tx() clears TXEMPTY when enabling TXEMPTY to avoid any previous TXEVENT event asserting the UART interrupt. This clear operation is done immediately after filling the TX FIFO. However, if the bytes inserted by cdns_uart_handle_tx() are consumed by the UART before the TXEMPTY is cleared, the clear operation eats the new TXEMPTY event as well, causing cdns_uart_isr() to never receive the TXEMPTY event. If there are bytes still queued in circbuf, TX will get stuck as they will never get transferred to FIFO (unless new bytes are queued to circbuf in which case .start_tx() is called again). While the racy missed TXEMPTY occurs fairly often with short data sequences (e.g. write 1 byte), in those cases circbuf is usually empty so no action on TXEMPTY would have been needed anyway. On the other hand, longer data sequences make the race much more unlikely as UART takes longer to consume the TX FIFO. Therefore it is rare for this race to cause visible issues in general. Fix the race by clearing the TXEMPTY bit in ISR *before* filling the FIFO. The TXEMPTY bit in ISR will only get asserted at the exact moment the TX FIFO *becomes* empty, so clearing the bit before filling FIFO does not cause an extra immediate assertion even if the FIFO is initially empty. This is hard to reproduce directly on a normal system, but inserting e.g. udelay(200) after cdns_uart_handle_tx(port), setting 4000000 baud, and then running "dd if=/dev/zero bs=128 of=/dev/ttyPS0 count=50" reliably reproduces the issue on my ZynqMP test system unless this fix is applied. Fixes: 85baf542d54e ("tty: xuartps: support 64 byte FIFO size") Signed-off-by: Anssi Hannula Link: https://lore.kernel.org/r/20211026102741.2910441-1-anssi.hannula@bitwise.fi Signed-off-by: Greg Kroah-Hartman Signed-off-by: Sasha Levin

serial: uartps: console_setup() can't be placed to init section

2019-04-20T07:07:52+00:00

[ Upstream commit 4bb1ce2350a598502b23088b169e16b43d4bc639 ] When console device is rebinded, console_setup() is called again. But marking it as __init means that function will be clear after boot is complete. If console device is binded again console_setup() is not found and error "Unable to handle kernel paging request at virtual address" is reported. Signed-off-by: Michal Simek Signed-off-by: Greg Kroah-Hartman Signed-off-by: Sasha Levin

serial: uartps: Fix stuck ISR if RX disabled with non-empty FIFO

2019-03-23T12:19:50+00:00

commit 7abab1605139bc41442864c18f9573440f7ca105 upstream. If RX is disabled while there are still unprocessed bytes in RX FIFO, cdns_uart_handle_rx() called from interrupt handler will get stuck in the receive loop as read bytes will not get removed from the RX FIFO and CDNS_UART_SR_RXEMPTY bit will never get set. Avoid the stuck handler by checking first if RX is disabled. port->lock protects against race with RX-disabling functions. This HW behavior was mentioned by Nathan Rossi in 43e98facc4a3 ("tty: xuartps: Fix RX hang, and TX corruption in termios call") which fixed a similar issue in cdns_uart_set_termios(). The behavior can also be easily verified by e.g. setting CDNS_UART_CR_RX_DIS at the beginning of cdns_uart_handle_rx() - the following loop will then get stuck. Resetting the FIFO using RXRST would not set RXEMPTY either so simply issuing a reset after RX-disable would not work. I observe this frequently on a ZynqMP board during heavy RX load at 1M baudrate when the reader process exits and thus RX gets disabled. Fixes: 61ec9016988f ("tty/serial: add support for Xilinx PS UART") Signed-off-by: Anssi Hannula Cc: stable@vger.kernel.org Signed-off-by: Greg Kroah-Hartman

serial: set suppress_bind_attrs flag only if builtin

2019-01-26T08:38:32+00:00

[ Upstream commit 646097940ad35aa2c1f2012af932d55976a9f255 ] When the test 'CONFIG_DEBUG_TEST_DRIVER_REMOVE=y' is enabled, arch_initcall(pl011_init) came before subsys_initcall(default_bdi_init). devtmpfs gets killed because we try to remove a file and decrement the wb reference count before the noop_backing_device_info gets initialized. [ 0.332075] Serial: AMBA PL011 UART driver [ 0.485276] 9000000.pl011: ttyAMA0 at MMIO 0x9000000 (irq = 39, base_baud = 0) is a PL011 rev1 [ 0.502382] console [ttyAMA0] enabled [ 0.515710] Unable to handle kernel paging request at virtual address 0000800074c12000 [ 0.516053] Mem abort info: [ 0.516222] ESR = 0x96000004 [ 0.516417] Exception class = DABT (current EL), IL = 32 bits [ 0.516641] SET = 0, FnV = 0 [ 0.516826] EA = 0, S1PTW = 0 [ 0.516984] Data abort info: [ 0.517149] ISV = 0, ISS = 0x00000004 [ 0.517339] CM = 0, WnR = 0 [ 0.517553] [0000800074c12000] user address but active_mm is swapper [ 0.517928] Internal error: Oops: 96000004 [#1] PREEMPT SMP [ 0.518305] Modules linked in: [ 0.518839] CPU: 0 PID: 13 Comm: kdevtmpfs Not tainted 4.19.0-rc5-next-20180928-00002-g2ba39ab0cd01-dirty #82 [ 0.519307] Hardware name: linux,dummy-virt (DT) [ 0.519681] pstate: 80000005 (Nzcv daif -PAN -UAO) [ 0.519959] pc : __destroy_inode+0x94/0x2a8 [ 0.520212] lr : __destroy_inode+0x78/0x2a8 [ 0.520401] sp : ffff0000098c3b20 [ 0.520590] x29: ffff0000098c3b20 x28: 00000000087a3714 [ 0.520904] x27: 0000000000002000 x26: 0000000000002000 [ 0.521179] x25: ffff000009583000 x24: 0000000000000000 [ 0.521467] x23: ffff80007bb52000 x22: ffff80007bbaa7c0 [ 0.521737] x21: ffff0000093f9338 x20: 0000000000000000 [ 0.522033] x19: ffff80007bbb05d8 x18: 0000000000000400 [ 0.522376] x17: 0000000000000000 x16: 0000000000000000 [ 0.522727] x15: 0000000000000400 x14: 0000000000000400 [ 0.523068] x13: 0000000000000001 x12: 0000000000000001 [ 0.523421] x11: 0000000000000000 x10: 0000000000000970 [ 0.523749] x9 : ffff0000098c3a60 x8 : ffff80007bbab190 [ 0.524017] x7 : ffff80007bbaa880 x6 : 0000000000000c88 [ 0.524305] x5 : ffff0000093d96c8 x4 : 61c8864680b583eb [ 0.524567] x3 : ffff0000093d6180 x2 : ffffffffffffffff [ 0.524872] x1 : 0000800074c12000 x0 : 0000800074c12000 [ 0.525207] Process kdevtmpfs (pid: 13, stack limit = 0x(____ptrval____)) [ 0.525529] Call trace: [ 0.525806] __destroy_inode+0x94/0x2a8 [ 0.526108] destroy_inode+0x34/0x88 [ 0.526370] evict+0x144/0x1c8 [ 0.526636] iput+0x184/0x230 [ 0.526871] dentry_unlink_inode+0x118/0x130 [ 0.527152] d_delete+0xd8/0xe0 [ 0.527420] vfs_unlink+0x240/0x270 [ 0.527665] handle_remove+0x1d8/0x330 [ 0.527875] devtmpfsd+0x138/0x1c8 [ 0.528085] kthread+0x14c/0x158 [ 0.528291] ret_from_fork+0x10/0x18 [ 0.528720] Code: 92800002 aa1403e0 d538d081 8b010000 (c85f7c04) [ 0.529367] ---[ end trace 5a3dee47727f877c ]--- Rework to set suppress_bind_attrs flag to avoid removing the device when CONFIG_DEBUG_TEST_DRIVER_REMOVE=y. This applies for pic32_uart and xilinx_uartps as well. Co-developed-by: Arnd Bergmann Signed-off-by: Arnd Bergmann Signed-off-by: Anders Roxell Signed-off-by: Greg Kroah-Hartman Signed-off-by: Sasha Levin

serial: uartps: Fix interrupt mask issue to handle the RX interrupts properly

2019-01-09T15:16:44+00:00

commit 260683137ab5276113fc322fdbbc578024185fee upstream. This patch Correct the RX interrupt mask value to handle the RX interrupts properly. Fixes: c8dbdc842d30 ("serial: xuartps: Rewrite the interrupt handling logic") Signed-off-by: Nava kishore Manne Cc: stable Signed-off-by: Michal Simek Signed-off-by: Greg Kroah-Hartman

serial: xuartps: Fix out-of-bounds access through DT alias

2018-05-25T14:13:13+00:00

[ Upstream commit e7d75e18d0fc3f7193b65282b651f980c778d935 ] The cdns_uart_port[] array is indexed using a value derived from the "serialN" alias in DT, which may lead to an out-of-bounds access. Fix this by adding a range check. Fixes: 928e9263492069ee ("tty: xuartps: Initialize ports according to aliases") Signed-off-by: Geert Uytterhoeven Reviewed-by: Michal Simek Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

serial: xuartps: Add new compatible string for ZynqMP

2016-10-27T14:00:32+00:00

This patch Adds the new compatible string for ZynqMP SoC. Signed-off-by: Nava kishore Manne Signed-off-by: Greg Kroah-Hartman

serial: xuartps: Add some register initialisation to cdns_early_console_setup()

2016-09-27T10:54:41+00:00

Add initialisation of control register and baud rate to cdns_early_console_setup(), required when running kernel standalone without a boot loader. Baud rate is only initialised when specified in earlycon command-line option, otherwise it is assumed this has been set by a boot loader. Updated Documentation/kernel-parameters.txt accordingly. Signed-off-by: Scott Telford Signed-off-by: Greg Kroah-Hartman

serial: xuartps: Removed unwanted checks while reading the error conditions

2016-09-27T10:54:41+00:00

This patch Remove the unwated checks while reading the parity,framing, overrun and Break detection errors. Signed-off-by: Nava kishore Manne Signed-off-by: Michal Simek [stelford@cadence.com: cherry picked from https://github.com/Xilinx/linux-xlnx commit b1cf74970df5470ffbc8e7876a9edf5e3498ef94] Signed-off-by: Scott Telford Signed-off-by: Greg Kroah-Hartman