lwn.git/drivers/tty/serial/imx.c, branch docs-mw

tty: serial: imx: keep dma request disabled before dma transfer setup

2026-03-12T14:25:39+00:00

Since sdma hardware configure postpone to transfer phase, have to disable dma request before dma transfer setup because there is a hardware limitation on sdma event enable(ENBLn) as below. Refer SDMA 2.6.28 Channel Enable RAM (SDMAARMx_CHNENBLn) section: "It is thus essential for the Arm platform to program them before any DMA request is triggered to the SDMA, otherwise an unpredictable combination of channels may be started." Signed-off-by: Robin Gong Signed-off-by: Sherry Sun Link: https://patch.msgid.link/20260312094526.297348-1-sherry.sun@nxp.com Signed-off-by: Greg Kroah-Hartman

tty: serial: imx: Add missing wakeup event reporting

2025-10-22T10:06:35+00:00

Current imx uart wakeup event would not report itself as wakeup source through sysfs. Add pm_wakeup_event() to support it. Signed-off-by: Sherry Sun Reviewed-by: Frank Li Link: https://patch.msgid.link/20251002045259.2725461-3-sherry.sun@nxp.com Signed-off-by: Greg Kroah-Hartman

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

2025-10-22T10:06:34+00:00

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

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