kernel/linux.git/drivers/tty/serial, branch v4.14.217

serial_core: Check for port state when tty is in error state

2020-12-29T12:46:49+00:00

commit 2f70e49ed860020f5abae4f7015018ebc10e1f0e upstream. At the moment opening a serial device node (such as /dev/ttyS3) succeeds even if there is no actual serial device behind it. Reading/writing/ioctls fail as expected because the uart port is not initialized (the type is PORT_UNKNOWN) and the TTY_IO_ERROR error state bit is set fot the tty. However setting line discipline does not have these checks 8250_port.c (8250 is the default choice made by univ8250_console_init()). As the result of PORT_UNKNOWN, uart_port::iobase is NULL which a platform translates onto some address accessing which produces a crash like below. This adds tty_port_initialized() to uart_set_ldisc() to prevent the crash. Found by syzkaller. Signed-off-by: Alexey Kardashevskiy Link: https://lore.kernel.org/r/20201203055834.45838-1-aik@ozlabs.ru Cc: stable Signed-off-by: Greg Kroah-Hartman

serial: 8250_omap: Avoid FIFO corruption caused by MDR1 access

2020-12-29T12:46:46+00:00

commit d96f04d347e4011977abdbb4da5d8f303ebd26f8 upstream. It has been observed that once per 300-1300 port openings the first transmitted byte is being corrupted on AM3352 ("v" written to FIFO appeared as "e" on the wire). It only happened if single byte has been transmitted right after port open, which means, DMA is not used for this transfer and the corruption never happened afterwards. Therefore I've carefully re-read the MDR1 errata (link below), which says "when accessing the MDR1 registers that causes a dummy under-run condition that will freeze the UART in IrDA transmission. In UART mode, this may corrupt the transferred data". Strictly speaking, omap_8250_mdr1_errataset() performs a read access and if the value is the same as should be written, exits without errata-recommended FIFO reset. A brief check of the serial_omap_mdr1_errataset() from the competing omap-serial driver showed it has no read access of MDR1. After removing the read access from omap_8250_mdr1_errataset() the data corruption never happened any more. Link: https://www.ti.com/lit/er/sprz360i/sprz360i.pdf Fixes: 61929cf0169d ("tty: serial: Add 8250-core based omap driver") Cc: stable@vger.kernel.org Signed-off-by: Alexander Sverdlin Link: https://lore.kernel.org/r/20201210055257.1053028-1-alexander.sverdlin@gmail.com Signed-off-by: Greg Kroah-Hartman

tty: serial: imx: keep console clocks always on

2020-11-24T12:05:52+00:00

commit e67c139c488e84e7eae6c333231e791f0e89b3fb upstream. For below code, there has chance to cause deadlock in SMP system: Thread 1: clk_enable_lock(); pr_info("debug message"); clk_enable_unlock(); Thread 2: imx_uart_console_write() clk_enable() clk_enable_lock(); Thread 1: Acuired clk enable_lock -> printk -> console_trylock_spinning Thread 2: console_unlock() -> imx_uart_console_write -> clk_disable -> Acquite clk enable_lock So the patch is to keep console port clocks always on like other console drivers. Fixes: 1cf93e0d5488 ("serial: imx: remove the uart_console() check") Acked-by: Uwe Kleine-König Signed-off-by: Fugang Duan Link: https://lore.kernel.org/r/20201111025136.29818-1-fugang.duan@nxp.com Cc: stable [fix up build warning - gregkh] Signed-off-by: Greg Kroah-Hartman

serial: txx9: add missing platform_driver_unregister() on error in serial_txx9_init

2020-11-10T09:29:06+00:00

commit 0c5fc92622ed5531ff324b20f014e9e3092f0187 upstream. Add the missing platform_driver_unregister() before return from serial_txx9_init in the error handling case when failed to register serial_txx9_pci_driver with macro ENABLE_SERIAL_TXX9_PCI defined. Fixes: ab4382d27412 ("tty: move drivers/serial/ to drivers/tty/serial/") Signed-off-by: Qinglang Miao Link: https://lore.kernel.org/r/20201103084942.109076-1-miaoqinglang@huawei.com Cc: stable Signed-off-by: Greg Kroah-Hartman

serial: 8250_mtk: Fix uart_get_baud_rate warning

2020-11-10T09:29:06+00:00

commit 912ab37c798770f21b182d656937072b58553378 upstream. Mediatek 8250 port supports speed higher than uartclk / 16. If the baud rates in both the new and the old termios setting are higher than uartclk / 16, the WARN_ON in uart_get_baud_rate() will be triggered. Passing NULL as the old termios so uart_get_baud_rate() will use uartclk / 16 - 1 as the new baud rate which will be replaced by the original baud rate later by tty_termios_encode_baud_rate() in mtk8250_set_termios(). Fixes: 551e553f0d4a ("serial: 8250_mtk: Fix high-speed baud rates clamping") Signed-off-by: Claire Chang Link: https://lore.kernel.org/r/20201102120749.374458-1-tientzu@chromium.org Cc: stable Signed-off-by: Greg Kroah-Hartman

tty: serial: fsl_lpuart: fix lpuart32_poll_get_char

2020-10-29T08:07:20+00:00

commit 29788ab1d2bf26c130de8f44f9553ee78a27e8d5 upstream. The watermark is set to 1, so we need to input two chars to trigger RDRF using the original logic. With the new logic, we could always get the char when there is data in FIFO. Suggested-by: Fugang Duan Signed-off-by: Peng Fan Link: https://lore.kernel.org/r/20200929095509.21680-1-peng.fan@nxp.com Cc: stable Signed-off-by: Greg Kroah-Hartman Signed-off-by: Greg Kroah-Hartman

tty: serial: earlycon dependency

2020-10-29T08:07:04+00:00

[ Upstream commit 0fb9342d06b0f667b915ba58bfefc030e534a218 ] parse_options() in drivers/tty/serial/earlycon.c calls uart_parse_earlycon in drivers/tty/serial/serial_core.c therefore selecting SERIAL_EARLYCON should automatically select SERIAL_CORE, otherwise will result in symbol not found error during linking if SERIAL_CORE is not configured as builtin Fixes: 9aac5887595b ("tty/serial: add generic serial earlycon") Signed-off-by: Tong Zhang Link: https://lore.kernel.org/r/20200828123949.2642-1-ztong0001@gmail.com Signed-off-by: Greg Kroah-Hartman Signed-off-by: Sasha Levin

tty: serial: samsung: Correct clock selection logic

2020-10-01T11:12:43+00:00

[ Upstream commit 7d31676a8d91dd18e08853efd1cb26961a38c6a6 ] Some variants of the samsung tty driver can pick which clock to use for their baud rate generation. In the DT conversion, a default clock was selected to be used if a specific one wasn't assigned and then a comparison of which clock rate worked better was done. Unfortunately, the comparison was implemented in such a way that only the default clock was ever actually compared. Fix this by iterating through all possible clocks, except when a specific clock has already been picked via clk_sel (which is only possible via board files). Signed-off-by: Jonathan Bakker Reviewed-by: Krzysztof Kozlowski Link: https://lore.kernel.org/r/BN6PR04MB06604E63833EA41837EBF77BA3A30@BN6PR04MB0660.namprd04.prod.outlook.com Signed-off-by: Greg Kroah-Hartman Signed-off-by: Sasha Levin

serial: uartps: Wait for tx_empty in console setup

2020-10-01T11:12:41+00:00

[ Upstream commit 42e11948ddf68b9f799cad8c0ddeab0a39da33e8 ] On some platforms, the log is corrupted while console is being registered. It is observed that when set_termios is called, there are still some bytes in the FIFO to be transmitted. So, wait for tx_empty inside cdns_uart_console_setup before calling set_termios. Signed-off-by: Raviteja Narayanam Reviewed-by: Shubhrajyoti Datta Link: https://lore.kernel.org/r/1586413563-29125-2-git-send-email-raviteja.narayanam@xilinx.com Signed-off-by: Greg Kroah-Hartman Signed-off-by: Sasha Levin

serial: 8250: 8250_omap: Terminate DMA before pushing data on RX timeout

2020-10-01T11:12:38+00:00

[ Upstream commit 7cf4df30a98175033e9849f7f16c46e96ba47f41 ] Terminate and flush DMA internal buffers, before pushing RX data to higher layer. Otherwise, this will lead to data corruption, as driver would end up pushing stale buffer data to higher layer while actual data is still stuck inside DMA hardware and has yet not arrived at the memory. While at that, replace deprecated dmaengine_terminate_all() with dmaengine_terminate_async(). Signed-off-by: Vignesh Raghavendra Link: https://lore.kernel.org/r/20200319110344.21348-2-vigneshr@ti.com Signed-off-by: Greg Kroah-Hartman Signed-off-by: Sasha Levin