kernel/linux.git/drivers/tty/serial/xilinx_uartps.c, branch v6.6.141

tty: xilinx_uartps: split sysrq handling

2025-02-17T08:40:43+00:00

commit b06f388994500297bb91be60ffaf6825ecfd2afe upstream. lockdep detects the following circular locking dependency: CPU 0 CPU 1 ========================== ============================ cdns_uart_isr() printk() uart_port_lock(port) console_lock() cdns_uart_console_write() if (!port->sysrq) uart_port_lock(port) uart_handle_break() port->sysrq = ... uart_handle_sysrq_char() printk() console_lock() The fixed commit attempts to avoid this situation by only taking the port lock in cdns_uart_console_write if port->sysrq unset. However, if (as shown above) cdns_uart_console_write runs before port->sysrq is set, then it will try to take the port lock anyway. This may result in a deadlock. Fix this by splitting sysrq handling into two parts. We use the prepare helper under the port lock and defer handling until we release the lock. Fixes: 74ea66d4ca06 ("tty: xuartps: Improve sysrq handling") Signed-off-by: Sean Anderson Cc: stable@vger.kernel.org # c980248179d: serial: xilinx_uartps: Use port lock wrappers Acked-by: John Ogness Link: https://lore.kernel.org/r/20250110213822.2107462-1-sean.anderson@linux.dev Signed-off-by: Sean Anderson Signed-off-by: Greg Kroah-Hartman

tty: serial: xilinx_uartps: Do not check for 0 return after calling platform_get_irq()

2023-08-04T13:06:01+00:00

Since commit a85a6c86c25b ("driver core: platform: Clarify that IRQ 0 is invalid"), there is no possible for platform_get_irq() to return 0. Use the return value from platform_get_irq(). Signed-off-by: Ruan Jinjie Link: https://lore.kernel.org/r/20230803091712.596987-1-ruanjinjie@huawei.com Signed-off-by: Greg Kroah-Hartman

serial: Make uart_remove_one_port() return void

2023-05-13T10:48:16+00:00

The return value is only ever used as a return value for remove callbacks of platform drivers. This return value is ignored by the driver core. (The only effect is an error message, but uart_remove_one_port() already emitted one in this case.) So the return value isn't used at all and uart_remove_one_port() can be changed to return void without any loss. Also this better matches the Linux device model as remove functions are not supposed to fail. Signed-off-by: Uwe Kleine-König Link: https://lore.kernel.org/r/20230512173810.131447-3-u.kleine-koenig@pengutronix.de Signed-off-by: Greg Kroah-Hartman

Merge tag 'tty-6.2-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty

2022-12-16T11:31:56+00:00

Pull tty/serial driver updates from Greg KH: "Here is the "big" set of tty/serial driver changes for 6.2-rc1. As in previous kernel releases, nothing big here at all, just some small incremental serial/tty layer cleanups and some individual driver additions and fixes. Highlights are: - serial helper macros from Jiri Slaby to reduce the amount of duplicated code in serial drivers - api cleanups and consolidations from Ilpo Järvinen in lots of serial drivers - the usual set of n_gsm fixes from Daniel Starke as that code gets exercised more - TIOCSTI is finally able to be disabled if requested (security hardening feature from Kees Cook) - fsl_lpuart driver fixes and features added - other small serial driver additions and fixes All of these have been in linux-next for a while with no reported problems" * tag 'tty-6.2-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: (97 commits) serial: atmel: don't stop the transmitter when doing PIO serial: atmel: cleanup atmel_start+stop_tx() tty: serial: fsl_lpuart: switch to new dmaengine_terminate_* API serial: sunsab: Fix error handling in sunsab_init() serial: altera_uart: fix locking in polling mode serial: pch: Fix PCI device refcount leak in pch_request_dma() tty: serial: fsl_lpuart: Use pm_ptr() to avoid need to make pm __maybe_unused tty: serial: fsl_lpuart: Add runtime pm support tty: serial: fsl_lpuart: enable wakeup source for lpuart serdev: Replace poll loop by readx_poll_timeout() macro tty: synclink_gt: unwind actions in error path of net device open serial: stm32: move dma_request_chan() before clk_prepare_enable() dt-bindings: serial: xlnx,opb-uartlite: Drop 'contains' from 'xlnx,use-parity' serial: pl011: Do not clear RX FIFO & RX interrupt in unthrottle. serial: amba-pl011: avoid SBSA UART accessing DMACR register tty: serial: altera_jtaguart: remove struct altera_jtaguart tty: serial: altera_jtaguart: use uart_port::read_status_mask tty: serial: altera_jtaguart: remove unused altera_jtaguart::sigs tty: serial: altera_jtaguart: remove flag from altera_jtaguart_rx_chars() n_tty: Rename tail to old_tail in n_tty_read() ...

tty: serial: xilinx_uartps: use console_is_registered()

2022-12-02T10:25:01+00:00

It is not reliable to check for CON_ENABLED in order to identify if a console is registered. Use console_is_registered() instead. Signed-off-by: John Ogness Reviewed-by: Petr Mladek Signed-off-by: Petr Mladek Link: https://lore.kernel.org/r/20221116162152.193147-30-john.ogness@linutronix.de

serial: xuartps: Use uart_xmit_advance()

2022-11-03T02:35:43+00:00

Take advantage of the new uart_xmit_advance() helper. Signed-off-by: Ilpo Järvinen Link: https://lore.kernel.org/r/20221019091151.6692-44-ilpo.jarvinen@linux.intel.com Signed-off-by: Greg Kroah-Hartman

serial: Make ->set_termios() old ktermios const

2022-08-30T12:22:35+00:00

There should be no reason to adjust old ktermios which is going to get discarded anyway. Reviewed-by: Andy Shevchenko Signed-off-by: Ilpo Järvinen Link: https://lore.kernel.org/r/20220816115739.10928-7-ilpo.jarvinen@linux.intel.com Signed-off-by: Greg Kroah-Hartman

tty: xilinx_uartps: Check the clk_enable return value

2022-08-30T11:26:01+00:00

Check the clk_enable return value. If clocks are not enabled the register accesses could hang the system so error out instead. Signed-off-by: Shubhrajyoti Datta Link: https://lore.kernel.org/r/20220729114748.18332-8-shubhrajyoti.datta@xilinx.com Signed-off-by: Greg Kroah-Hartman

tty: xilinx_uartps: Add timeout waiting for loop

2022-08-30T11:26:01+00:00

There is a potential infinite loop while waiting for the the TXFULL to deassert. Adds the error message and timeout to avoid infinite loop if it fails to get the TX fifo not full. Signed-off-by: Shubhrajyoti Datta Link: https://lore.kernel.org/r/20220729114748.18332-7-shubhrajyoti.datta@xilinx.com Signed-off-by: Greg Kroah-Hartman

tty: xilinx_uartps: Prevent writes when the controller is disabled

2022-08-30T11:26:01+00:00

Prevent writing to the fifo if the controller is disabled. Signed-off-by: Shubhrajyoti Datta Link: https://lore.kernel.org/r/20220729114748.18332-6-shubhrajyoti.datta@xilinx.com Signed-off-by: Greg Kroah-Hartman