kernel/linux.git/drivers/tty/serial/imx.c, branch v6.18.21

tty: serial: imx: Only configure the wake register when device is set as wakeup source

2025-12-18T13:02:34+00:00

[ Upstream commit d55f3d2375ceeb08330d30f1e08196993c0b6583 ] Currently, the i.MX UART driver enables wake-related registers for all UART devices by default. However, this is unnecessary for devices that are not configured as wakeup sources. To address this, add a device_may_wakeup() check before configuring the UART wake-related registers. Fixes: db1a9b55004c ("tty: serial: imx: Allow UART to be a source for wakeup") Signed-off-by: Sherry Sun Reviewed-by: Frank Li Link: https://patch.msgid.link/20251002045259.2725461-2-sherry.sun@nxp.com Signed-off-by: Greg Kroah-Hartman Signed-off-by: Sasha Levin

serial: imx: Restore original RXTL for console to fix data loss

2025-06-24T14:34:21+00:00

Commit 7a637784d517 ("serial: imx: reduce RX interrupt frequency") introduced a regression on the i.MX6UL EVK board. The issue can be reproduced with the following steps: - Open vi on the board. - Paste a text file (~150 characters). - Save the file, then repeat the process. - Compare the sha256sum of the saved files. The checksums do not match due to missing characters or entire lines. Fix this by restoring the RXTL value to 1 when the UART is used as a console. This ensures timely RX interrupts and reliable data reception in console mode. With this change, pasted content is saved correctly, and checksums are always consistent. Cc: stable Fixes: 7a637784d517 ("serial: imx: reduce RX interrupt frequency") Signed-off-by: Fabio Estevam Reviewed-by: Stefan Wahren Link: https://lore.kernel.org/r/20250619114617.2791939-1-festevam@gmail.com Signed-off-by: Greg Kroah-Hartman

treewide, timers: Rename from_timer() to timer_container_of()

2025-06-08T07:07:37+00:00

Move this API to the canonical timer_*() namespace. [ tglx: Redone against pre rc1 ] Signed-off-by: Ingo Molnar Signed-off-by: Thomas Gleixner Link: https://lore.kernel.org/all/aB2X0jCKQO56WdMt@gmail.com

treewide: Switch/rename to timer_delete[_sync]()

2025-04-05T08:30:12+00:00

timer_delete[_sync]() replaces del_timer[_sync](). Convert the whole tree over and remove the historical wrapper inlines. Conversion was done with coccinelle plus manual fixups where necessary. Signed-off-by: Thomas Gleixner Signed-off-by: Ingo Molnar

serial: imx: Switch to use hrtimer_setup()

2025-02-20T14:38:31+00:00

hrtimer_setup() takes the callback function pointer as argument and initializes the timer completely. Replace hrtimer_init() and the open coded initialization of hrtimer::function with the new setup mechanism. Patch was created by using Coccinelle. Acked-by: Zack Rusin Signed-off-by: Nam Cao Cc: Greg Kroah-Hartman Link: https://lore.kernel.org/r/ad27070bc67c13f8a9acbd5cbf4cbae72797e3e1.1738746904.git.namcao@linutronix.de Signed-off-by: Greg Kroah-Hartman

serial: mctrl_gpio: split disable_ms into sync and no_sync APIs

2025-02-19T14:08:36+00:00

The following splat has been observed on a SAMA5D27 platform using atmel_serial: BUG: sleeping function called from invalid context at kernel/irq/manage.c:738 in_atomic(): 1, irqs_disabled(): 128, non_block: 0, pid: 27, name: kworker/u5:0 preempt_count: 1, expected: 0 INFO: lockdep is turned off. irq event stamp: 0 hardirqs last enabled at (0): [<00000000>] 0x0 hardirqs last disabled at (0): [] copy_process+0x1c4c/0x7bec softirqs last enabled at (0): [] copy_process+0x1ca0/0x7bec softirqs last disabled at (0): [<00000000>] 0x0 CPU: 0 UID: 0 PID: 27 Comm: kworker/u5:0 Not tainted 6.13.0-rc7+ #74 Hardware name: Atmel SAMA5 Workqueue: hci0 hci_power_on [bluetooth] Call trace: unwind_backtrace from show_stack+0x18/0x1c show_stack from dump_stack_lvl+0x44/0x70 dump_stack_lvl from __might_resched+0x38c/0x598 __might_resched from disable_irq+0x1c/0x48 disable_irq from mctrl_gpio_disable_ms+0x74/0xc0 mctrl_gpio_disable_ms from atmel_disable_ms.part.0+0x80/0x1f4 atmel_disable_ms.part.0 from atmel_set_termios+0x764/0x11e8 atmel_set_termios from uart_change_line_settings+0x15c/0x994 uart_change_line_settings from uart_set_termios+0x2b0/0x668 uart_set_termios from tty_set_termios+0x600/0x8ec tty_set_termios from ttyport_set_flow_control+0x188/0x1e0 ttyport_set_flow_control from wilc_setup+0xd0/0x524 [hci_wilc] wilc_setup [hci_wilc] from hci_dev_open_sync+0x330/0x203c [bluetooth] hci_dev_open_sync [bluetooth] from hci_dev_do_open+0x40/0xb0 [bluetooth] hci_dev_do_open [bluetooth] from hci_power_on+0x12c/0x664 [bluetooth] hci_power_on [bluetooth] from process_one_work+0x998/0x1a38 process_one_work from worker_thread+0x6e0/0xfb4 worker_thread from kthread+0x3d4/0x484 kthread from ret_from_fork+0x14/0x28 This warning is emitted when trying to toggle, at the highest level, some flow control (with serdev_device_set_flow_control) in a device driver. At the lowest level, the atmel_serial driver is using serial_mctrl_gpio lib to enable/disable the corresponding IRQs accordingly. The warning emitted by CONFIG_DEBUG_ATOMIC_SLEEP is due to disable_irq (called in mctrl_gpio_disable_ms) being possibly called in some atomic context (some tty drivers perform modem lines configuration in regions protected by port lock). Split mctrl_gpio_disable_ms into two differents APIs, a non-blocking one and a blocking one. Replace mctrl_gpio_disable_ms calls with the relevant version depending on whether the call is protected by some port lock. Suggested-by: Jiri Slaby Signed-off-by: Alexis Lothoré Acked-by: Richard Genoud Link: https://lore.kernel.org/r/20250217-atomic_sleep_mctrl_serial_gpio-v3-1-59324b313eef@bootlin.com Signed-off-by: Greg Kroah-Hartman

serial: imx: Use uart_port_lock_irq() instead of uart_port_lock()

2024-12-23T18:01:40+00:00

When executing 'echo mem > /sys/power/state', the following deadlock occurs. Since there is output during the serial port entering the suspend process, the suspend will be interrupted, resulting in the nesting of locks. Therefore, use uart_port_lock_irq() instead of uart_port_unlock(). WARNING: inconsistent lock state 6.12.0-rc2-00002-g3c199ed5bd64-dirty #23 Not tainted -------------------------------- inconsistent {IN-HARDIRQ-W} -> {HARDIRQ-ON-W} usage. sh/494 [HC0[0]:SC0[0]:HE1:SE1] takes: c4db5850 (&port_lock_key){?.-.}-{3:3}, at: imx_uart_enable_wakeup+0x14/0x254 {IN-HARDIRQ-W} state was registered at: lock_acquire+0x104/0x348 _raw_spin_lock+0x48/0x84 imx_uart_int+0x14/0x4dc __handle_irq_event_percpu+0xac/0x2fc handle_irq_event_percpu+0xc/0x40 handle_irq_event+0x38/0x8c handle_fasteoi_irq+0xb4/0x1b8 handle_irq_desc+0x1c/0x2c gic_handle_irq+0x6c/0xa0 generic_handle_arch_irq+0x2c/0x64 call_with_stack+0x18/0x20 __irq_svc+0x9c/0xbc _raw_spin_unlock_irqrestore+0x2c/0x48 uart_write+0xd8/0x3a0 do_output_char+0x1a8/0x1e4 n_tty_write+0x224/0x440 file_tty_write.constprop.0+0x124/0x250 do_iter_readv_writev+0x100/0x1e0 vfs_writev+0xc4/0x448 do_writev+0x68/0xf8 ret_fast_syscall+0x0/0x1c irq event stamp: 31593 hardirqs last enabled at (31593): [] _raw_spin_unlock_irqrestore+0x44/0x48 hardirqs last disabled at (31592): [] clk_enable_lock+0x60/0x120 softirqs last enabled at (30334): [] handle_softirqs+0x2cc/0x478 softirqs last disabled at (30325): [] __irq_exit_rcu+0x120/0x15c other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(&port_lock_key); lock(&port_lock_key); Fixes: 3c199ed5bd64 ("serial: imx: Grab port lock in imx_uart_enable_wakeup()") Signed-off-by: Xiaolei Wang Reviewed-by: Lucas Stach Reviewed-by: Fabio Estevam Link: https://lore.kernel.org/r/20241210233613.2881264-1-xiaolei.wang@windriver.com Signed-off-by: Greg Kroah-Hartman

Merge 6.12-rc4 into tty-next

2024-10-21T06:51:39+00:00

We need the tty/serial fixes in here as well Signed-off-by: Greg Kroah-Hartman

serial: imx: Update mctrl old_status on RTSD interrupt

2024-10-11T06:28:45+00:00

When sending data using DMA at high baudrate (4 Mbdps in local test case) to a device with small RX buffer which keeps asserting RTS after every received byte, it is possible that the iMX UART driver would not recognize the falling edge of RTS input signal and get stuck, unable to transmit any more data. This condition happens when the following sequence of events occur: - imx_uart_mctrl_check() is called at some point and takes a snapshot of UART control signal status into sport->old_status using imx_uart_get_hwmctrl(). The RTSS/TIOCM_CTS bit is of interest here (*). - DMA transfer occurs, the remote device asserts RTS signal after each byte. The i.MX UART driver recognizes each such RTS signal change, raises an interrupt with USR1 register RTSD bit set, which leads to invocation of __imx_uart_rtsint(), which calls uart_handle_cts_change(). - If the RTS signal is deasserted, uart_handle_cts_change() clears port->hw_stopped and unblocks the port for further data transfers. - If the RTS is asserted, uart_handle_cts_change() sets port->hw_stopped and blocks the port for further data transfers. This may occur as the last interrupt of a transfer, which means port->hw_stopped remains set and the port remains blocked (**). - Any further data transfer attempts will trigger imx_uart_mctrl_check(), which will read current status of UART control signals by calling imx_uart_get_hwmctrl() (***) and compare it with sport->old_status . - If current status differs from sport->old_status for RTS signal, uart_handle_cts_change() is called and possibly unblocks the port by clearing port->hw_stopped . - If current status does not differ from sport->old_status for RTS signal, no action occurs. This may occur in case prior snapshot (*) was taken before any transfer so the RTS is deasserted, current snapshot (***) was taken after a transfer and therefore RTS is deasserted again, which means current status and sport->old_status are identical. In case (**) triggered when RTS got asserted, and made port->hw_stopped set, the port->hw_stopped will remain set because no change on RTS line is recognized by this driver and uart_handle_cts_change() is not called from here to unblock the port->hw_stopped. Update sport->old_status in __imx_uart_rtsint() accordingly to make imx_uart_mctrl_check() detect such RTS change. Note that TIOCM_CAR and TIOCM_RI bits in sport->old_status do not suffer from this problem. Fixes: ceca629e0b48 ("[ARM] 2971/1: i.MX uart handle rts irq") Cc: stable Reviewed-by: Esben Haabendal Signed-off-by: Marek Vasut Link: https://lore.kernel.org/r/20241002184133.19427-1-marex@denx.de Signed-off-by: Greg Kroah-Hartman

serial: imx: Switch to nbcon console

2024-10-11T06:17:33+00:00

Implements the necessary callbacks to switch the imx console driver to perform as an nbcon console. Add implementations for the nbcon consoles (write_atomic, write_thread, driver_enter, driver_exit) and add CON_NBCON to the initial flags. The legacy code is kept in order to easily switch back to legacy mode by defining CONFIG_SERIAL_IMX_LEGACY_CONSOLE. Signed-off-by: Esben Haabendal Link: https://lore.kernel.org/r/20240913-serial-imx-nbcon-v3-1-4c627302335b@geanix.com Signed-off-by: Greg Kroah-Hartman