linux-stable.git/drivers/tty/serial, branch linux-6.14.y Linux kernel stable tree serial: jsm: fix NPE during jsm_uart_port_init 2025-06-10T11:15:57+00:00 Dustin Lundquist dustin@null-ptr.net 2025-05-06T18:18:45+00:00 a14c0d2eb3f0b1836fdec22908b87ecffd2ac844 commit e3975aa899c0a3bbc10d035e699b142cd1373a71 upstream. No device was set which caused serial_base_ctrl_add to crash. BUG: kernel NULL pointer dereference, address: 0000000000000050 Oops: Oops: 0000 [#1] PREEMPT SMP NOPTI CPU: 16 UID: 0 PID: 368 Comm: (udev-worker) Not tainted 6.12.25-amd64 #1 Debian 6.12.25-1 RIP: 0010:serial_base_ctrl_add+0x96/0x120 Call Trace: <TASK> serial_core_register_port+0x1a0/0x580 ? __setup_irq+0x39c/0x660 ? __kmalloc_cache_noprof+0x111/0x310 jsm_uart_port_init+0xe8/0x180 [jsm] jsm_probe_one+0x1f4/0x410 [jsm] local_pci_probe+0x42/0x90 pci_device_probe+0x22f/0x270 really_probe+0xdb/0x340 ? pm_runtime_barrier+0x54/0x90 ? __pfx___driver_attach+0x10/0x10 __driver_probe_device+0x78/0x110 driver_probe_device+0x1f/0xa0 __driver_attach+0xba/0x1c0 bus_for_each_dev+0x8c/0xe0 bus_add_driver+0x112/0x1f0 driver_register+0x72/0xd0 jsm_init_module+0x36/0xff0 [jsm] ? __pfx_jsm_init_module+0x10/0x10 [jsm] do_one_initcall+0x58/0x310 do_init_module+0x60/0x230 Tested with Digi Neo PCIe 8 port card. Fixes: 84a9582fd203 ("serial: core: Start managing serial controllers to enable runtime PM") Cc: stable <stable@kernel.org> Signed-off-by: Dustin Lundquist <dustin@null-ptr.net> Link: https://lore.kernel.org/r/3f31d4f75863614655c4673027a208be78d022ec.camel@null-ptr.net Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit e3975aa899c0a3bbc10d035e699b142cd1373a71 upstream.

No device was set which caused serial_base_ctrl_add to crash.

 BUG: kernel NULL pointer dereference, address: 0000000000000050
 Oops: Oops: 0000 [#1] PREEMPT SMP NOPTI
 CPU: 16 UID: 0 PID: 368 Comm: (udev-worker) Not tainted 6.12.25-amd64 #1  Debian 6.12.25-1
 RIP: 0010:serial_base_ctrl_add+0x96/0x120
 Call Trace:
  <TASK>
  serial_core_register_port+0x1a0/0x580
  ? __setup_irq+0x39c/0x660
  ? __kmalloc_cache_noprof+0x111/0x310
  jsm_uart_port_init+0xe8/0x180 [jsm]
  jsm_probe_one+0x1f4/0x410 [jsm]
  local_pci_probe+0x42/0x90
  pci_device_probe+0x22f/0x270
  really_probe+0xdb/0x340
  ? pm_runtime_barrier+0x54/0x90
  ? __pfx___driver_attach+0x10/0x10
  __driver_probe_device+0x78/0x110
  driver_probe_device+0x1f/0xa0
  __driver_attach+0xba/0x1c0
  bus_for_each_dev+0x8c/0xe0
  bus_add_driver+0x112/0x1f0
  driver_register+0x72/0xd0
  jsm_init_module+0x36/0xff0 [jsm]
  ? __pfx_jsm_init_module+0x10/0x10 [jsm]
  do_one_initcall+0x58/0x310
  do_init_module+0x60/0x230

Tested with Digi Neo PCIe 8 port card.

Fixes: 84a9582fd203 ("serial: core: Start managing serial controllers to enable runtime PM")
Cc: stable <stable@kernel.org>
Signed-off-by: Dustin Lundquist <dustin@null-ptr.net>
Link: https://lore.kernel.org/r/3f31d4f75863614655c4673027a208be78d022ec.camel@null-ptr.net
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
serial: sh-sci: Save and restore more registers 2025-05-29T09:13:49+00:00 Geert Uytterhoeven geert+renesas@glider.be 2025-03-04T19:06:11+00:00 9f6257820aafb7e350134a5ed8779e32208e43ba [ Upstream commit 81100b9a7b0515132996d62a7a676a77676cb6e3 ] On (H)SCIF with a Baud Rate Generator for External Clock (BRG), there are multiple ways to configure the requested serial speed. If firmware uses a different method than Linux, and if any debug info is printed after the Bit Rate Register (SCBRR) is restored, but before termios is reconfigured (which configures the alternative method), the system may lock-up during resume. Fix this by saving and restoring the contents of the BRG Frequency Division (SCDL) and Clock Select (SCCKS) registers as well. Also save and restore the HSCIF's Sampling Rate Register (HSSRR), which configures the sampling point, and the SCIFA/SCIFB's Serial Port Control and Data Registers (SCPCR/SCPDR), which configure the optional control flow signals. After this, all registers that are not saved/restored are either: - read-only, - write-only, - status registers containing flags with clear-after-set semantics, - FIFO Data Count Trigger registers, which do not matter much for the serial console. Fixes: 22a6984c5b5df8ea ("serial: sh-sci: Update the suspend/resume support") Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Tested-by: Claudiu Beznea <claudiu.beznea.uj@bp.renesas.com> Reviewed-by: Claudiu Beznea <claudiu.beznea.uj@bp.renesas.com> Link: https://lore.kernel.org/r/11c2eab45d48211e75d8b8202cce60400880fe55.1741114989.git.geert+renesas@glider.be Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit 81100b9a7b0515132996d62a7a676a77676cb6e3 ]

On (H)SCIF with a Baud Rate Generator for External Clock (BRG), there
are multiple ways to configure the requested serial speed.  If firmware
uses a different method than Linux, and if any debug info is printed
after the Bit Rate Register (SCBRR) is restored, but before termios is
reconfigured (which configures the alternative method), the system may
lock-up during resume.

Fix this by saving and restoring the contents of the BRG Frequency
Division (SCDL) and Clock Select (SCCKS) registers as well.

Also save and restore the HSCIF's Sampling Rate Register (HSSRR), which
configures the sampling point, and the SCIFA/SCIFB's Serial Port Control
and Data Registers (SCPCR/SCPDR), which configure the optional control
flow signals.

After this, all registers that are not saved/restored are either:
  - read-only,
  - write-only,
  - status registers containing flags with clear-after-set semantics,
  - FIFO Data Count Trigger registers, which do not matter much for
    the serial console.

Fixes: 22a6984c5b5df8ea ("serial: sh-sci: Update the suspend/resume support")
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Tested-by: Claudiu Beznea <claudiu.beznea.uj@bp.renesas.com>
Reviewed-by: Claudiu Beznea <claudiu.beznea.uj@bp.renesas.com>
Link: https://lore.kernel.org/r/11c2eab45d48211e75d8b8202cce60400880fe55.1741114989.git.geert+renesas@glider.be
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
serial: sh-sci: Update the suspend/resume support 2025-05-29T09:13:23+00:00 Claudiu Beznea claudiu.beznea.uj@bp.renesas.com 2025-02-07T11:33:13+00:00 694bffbaac30d92cece71c4a91b5ace09ec0e3b2 [ Upstream commit 22a6984c5b5df8eab864d7f3e8b94d5a554d31ab ] The Renesas RZ/G3S supports a power saving mode where power to most of the SoC components is turned off. When returning from this power saving mode, SoC components need to be re-configured. The SCIFs on the Renesas RZ/G3S need to be re-configured as well when returning from this power saving mode. The sh-sci code already configures the SCIF clocks, power domain and registers by calling uart_resume_port() in sci_resume(). On suspend path the SCIF UART ports are suspended accordingly (by calling uart_suspend_port() in sci_suspend()). The only missing setting is the reset signal. For this assert/de-assert the reset signal on driver suspend/resume. In case the no_console_suspend is specified by the user, the registers need to be saved on suspend path and restore on resume path. To do this the sci_console_save()/sci_console_restore() functions were added. There is no need to cache/restore the status or FIFO registers. Only the control registers. The registers that will be saved/restored on suspend/resume are specified by the struct sci_suspend_regs data structure. Signed-off-by: Claudiu Beznea <claudiu.beznea.uj@bp.renesas.com> Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be> Link: https://lore.kernel.org/r/20250207113313.545432-1-claudiu.beznea.uj@bp.renesas.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit 22a6984c5b5df8eab864d7f3e8b94d5a554d31ab ]

The Renesas RZ/G3S supports a power saving mode where power to most of the
SoC components is turned off. When returning from this power saving mode,
SoC components need to be re-configured.

The SCIFs on the Renesas RZ/G3S need to be re-configured as well when
returning from this power saving mode. The sh-sci code already configures
the SCIF clocks, power domain and registers by calling uart_resume_port()
in sci_resume(). On suspend path the SCIF UART ports are suspended
accordingly (by calling uart_suspend_port() in sci_suspend()). The only
missing setting is the reset signal. For this assert/de-assert the reset
signal on driver suspend/resume.

In case the no_console_suspend is specified by the user, the registers need
to be saved on suspend path and restore on resume path. To do this the
sci_console_save()/sci_console_restore() functions were added. There is no
need to cache/restore the status or FIFO registers. Only the control
registers. The registers that will be saved/restored on suspend/resume are
specified by the struct sci_suspend_regs data structure.

Signed-off-by: Claudiu Beznea <claudiu.beznea.uj@bp.renesas.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://lore.kernel.org/r/20250207113313.545432-1-claudiu.beznea.uj@bp.renesas.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
serial: mctrl_gpio: split disable_ms into sync and no_sync APIs 2025-05-29T09:13:16+00:00 Alexis Lothoré alexis.lothore@bootlin.com 2025-02-17T06:21:53+00:00 7187ec6b0b9ff22ebac2c3bb4178b7dbbdc0a55a [ Upstream commit 1bd2aad57da95f7f2d2bb52f7ad15c0f4993a685 ] 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): [<c01588f0>] copy_process+0x1c4c/0x7bec softirqs last enabled at (0): [<c0158944>] 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 <jirislaby@kernel.org> Signed-off-by: Alexis Lothoré <alexis.lothore@bootlin.com> Acked-by: Richard Genoud <richard.genoud@bootlin.com> Link: https://lore.kernel.org/r/20250217-atomic_sleep_mctrl_serial_gpio-v3-1-59324b313eef@bootlin.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit 1bd2aad57da95f7f2d2bb52f7ad15c0f4993a685 ]

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): [<c01588f0>] copy_process+0x1c4c/0x7bec
softirqs last  enabled at (0): [<c0158944>] 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 <jirislaby@kernel.org>
Signed-off-by: Alexis Lothoré <alexis.lothore@bootlin.com>
Acked-by: Richard Genoud <richard.genoud@bootlin.com>
Link: https://lore.kernel.org/r/20250217-atomic_sleep_mctrl_serial_gpio-v3-1-59324b313eef@bootlin.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
serial: sifive: lock port in startup()/shutdown() callbacks 2025-05-02T06:01:52+00:00 Ryo Takakura ryotkkr98@gmail.com 2025-04-12T00:18:47+00:00 3774544de496bb7fbe27965b59f6c6451fa17061 commit e1ca3ff28ab1e2c1e70713ef3fa7943c725742c3 upstream. startup()/shutdown() callbacks access SIFIVE_SERIAL_IE_OFFS. The register is also accessed from write() callback. If console were printing and startup()/shutdown() callback gets called, its access to the register could be overwritten. Add port->lock to startup()/shutdown() callbacks to make sure their access to SIFIVE_SERIAL_IE_OFFS is synchronized against write() callback. Fixes: 45c054d0815b ("tty: serial: add driver for the SiFive UART") Signed-off-by: Ryo Takakura <ryotkkr98@gmail.com> Reviewed-by: Petr Mladek <pmladek@suse.com> Cc: stable@vger.kernel.org Reviewed-by: John Ogness <john.ogness@linutronix.de> Rule: add Link: https://lore.kernel.org/stable/20250330003522.386632-1-ryotkkr98%40gmail.com Link: https://lore.kernel.org/r/20250412001847.183221-1-ryotkkr98@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit e1ca3ff28ab1e2c1e70713ef3fa7943c725742c3 upstream.

startup()/shutdown() callbacks access SIFIVE_SERIAL_IE_OFFS.
The register is also accessed from write() callback.

If console were printing and startup()/shutdown() callback
gets called, its access to the register could be overwritten.

Add port->lock to startup()/shutdown() callbacks to make sure
their access to SIFIVE_SERIAL_IE_OFFS is synchronized against
write() callback.

Fixes: 45c054d0815b ("tty: serial: add driver for the SiFive UART")
Signed-off-by: Ryo Takakura <ryotkkr98@gmail.com>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Cc: stable@vger.kernel.org
Reviewed-by: John Ogness <john.ogness@linutronix.de>
Rule: add
Link: https://lore.kernel.org/stable/20250330003522.386632-1-ryotkkr98%40gmail.com
Link: https://lore.kernel.org/r/20250412001847.183221-1-ryotkkr98@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
serial: msm: Configure correct working mode before starting earlycon 2025-05-02T06:01:52+00:00 Stephan Gerhold stephan.gerhold@linaro.org 2025-04-08T17:22:47+00:00 a17c7fed6590436e843fe161e6ab26cc46c701da commit 7094832b5ac861b0bd7ed8866c93cb15ef619996 upstream. The MSM UART DM controller supports different working modes, e.g. DMA or the "single-character mode", where all reads/writes operate on a single character rather than 4 chars (32-bit) at once. When using earlycon, __msm_console_write() always writes 4 characters at a time, but we don't know which mode the bootloader was using and we don't set the mode either. This causes garbled output if the bootloader was using the single-character mode, because only every 4th character appears in the serial console, e.g. "[ 00oni pi 000xf0[ 00i s 5rm9(l)l s 1 1 SPMTA 7:C 5[ 00A ade k d[ 00ano:ameoi .Q1B[ 00ac _idaM00080oo'" If the bootloader was using the DMA ("DM") mode, output would likely fail entirely. Later, when the full serial driver probes, the port is re-initialized and output works as expected. Fix this also for earlycon by clearing the DMEN register and reset+re-enable the transmitter to apply the change. This ensures the transmitter is in the expected state before writing any output. Cc: stable <stable@kernel.org> Fixes: 0efe72963409 ("tty: serial: msm: Add earlycon support") Signed-off-by: Stephan Gerhold <stephan.gerhold@linaro.org> Reviewed-by: Neil Armstrong <neil.armstrong@linaro.org> Link: https://lore.kernel.org/r/20250408-msm-serial-earlycon-v1-1-429080127530@linaro.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 7094832b5ac861b0bd7ed8866c93cb15ef619996 upstream.

The MSM UART DM controller supports different working modes, e.g. DMA or
the "single-character mode", where all reads/writes operate on a single
character rather than 4 chars (32-bit) at once. When using earlycon,
__msm_console_write() always writes 4 characters at a time, but we don't
know which mode the bootloader was using and we don't set the mode either.

This causes garbled output if the bootloader was using the single-character
mode, because only every 4th character appears in the serial console, e.g.

  "[ 00oni pi  000xf0[ 00i s 5rm9(l)l s 1  1 SPMTA 7:C 5[ 00A ade k d[
   00ano:ameoi .Q1B[ 00ac _idaM00080oo'"

If the bootloader was using the DMA ("DM") mode, output would likely fail
entirely. Later, when the full serial driver probes, the port is
re-initialized and output works as expected.

Fix this also for earlycon by clearing the DMEN register and
reset+re-enable the transmitter to apply the change. This ensures the
transmitter is in the expected state before writing any output.

Cc: stable <stable@kernel.org>
Fixes: 0efe72963409 ("tty: serial: msm: Add earlycon support")
Signed-off-by: Stephan Gerhold <stephan.gerhold@linaro.org>
Reviewed-by: Neil Armstrong <neil.armstrong@linaro.org>
Link: https://lore.kernel.org/r/20250408-msm-serial-earlycon-v1-1-429080127530@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
tty: serial: lpuart: only disable CTS instead of overwriting the whole UARTMODIR register 2025-04-10T12:44:43+00:00 Sherry Sun sherry.sun@nxp.com 2025-03-07T06:54:46+00:00 80a72e6380fd2402475e7f747ce4952aac3e17be [ Upstream commit e98ab45ec5182605d2e00114cba3bbf46b0ea27f ] No need to overwrite the whole UARTMODIR register before waiting the transmit engine complete, actually our target here is only to disable CTS flow control to avoid the dirty data in TX FIFO may block the transmit engine complete. Also delete the following duplicate CTS disable configuration. Fixes: d5a2e0834364 ("tty: serial: lpuart: disable flow control while waiting for the transmit engine to complete") Cc: stable <stable@kernel.org> Signed-off-by: Sherry Sun <sherry.sun@nxp.com> Link: https://lore.kernel.org/r/20250307065446.1122482-1-sherry.sun@nxp.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit e98ab45ec5182605d2e00114cba3bbf46b0ea27f ]

No need to overwrite the whole UARTMODIR register before waiting the
transmit engine complete, actually our target here is only to disable
CTS flow control to avoid the dirty data in TX FIFO may block the
transmit engine complete.
Also delete the following duplicate CTS disable configuration.

Fixes: d5a2e0834364 ("tty: serial: lpuart: disable flow control while waiting for the transmit engine to complete")
Cc: stable <stable@kernel.org>
Signed-off-by: Sherry Sun <sherry.sun@nxp.com>
Link: https://lore.kernel.org/r/20250307065446.1122482-1-sherry.sun@nxp.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
tty: serial: fsl_lpuart: Fix unused variable 'sport' build warning 2025-04-10T12:44:43+00:00 Sherry Sun sherry.sun@nxp.com 2025-03-24T02:10:51+00:00 fa00a5fccd0ce42a444b69119601737ef36e62df commit 9f8fe348ac9544f6855f82565e754bf085d81f88 upstream. Remove the unused variable 'sport' to avoid the kernel build warning. Fixes: 3cc16ae096f1 ("tty: serial: fsl_lpuart: use port struct directly to simply code") Reported-by: kernel test robot <lkp@intel.com> Closes: https://lore.kernel.org/oe-kbuild-all/202503210614.2qGlnbIq-lkp@intel.com/ Signed-off-by: Sherry Sun <sherry.sun@nxp.com> Link: https://lore.kernel.org/r/20250324021051.162676-1-sherry.sun@nxp.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 9f8fe348ac9544f6855f82565e754bf085d81f88 upstream.

Remove the unused variable 'sport' to avoid the kernel build warning.

Fixes: 3cc16ae096f1 ("tty: serial: fsl_lpuart: use port struct directly to simply code")
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202503210614.2qGlnbIq-lkp@intel.com/
Signed-off-by: Sherry Sun <sherry.sun@nxp.com>
Link: https://lore.kernel.org/r/20250324021051.162676-1-sherry.sun@nxp.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
tty: serial: fsl_lpuart: use port struct directly to simply code 2025-04-10T12:44:43+00:00 Sherry Sun sherry.sun@nxp.com 2025-03-12T02:39:03+00:00 2526110174c7b5e33f3ebac3e1540443b0715dbe commit 3cc16ae096f164ae0c6b98416c25a01db5f3a529 upstream. Most lpuart functions have the parameter struct uart_port *port, but still use the &sport->port to get the uart_port instead of use it directly, let's simply the code logic, directly use this struct instead of covert it from struct sport. Signed-off-by: Sherry Sun <sherry.sun@nxp.com> Link: https://lore.kernel.org/r/20250312023904.1343351-3-sherry.sun@nxp.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 3cc16ae096f164ae0c6b98416c25a01db5f3a529 upstream.

Most lpuart functions have the parameter struct uart_port *port, but
still use the &sport->port to get the uart_port instead of use it
directly, let's simply the code logic, directly use this struct instead
of covert it from struct sport.

Signed-off-by: Sherry Sun <sherry.sun@nxp.com>
Link: https://lore.kernel.org/r/20250312023904.1343351-3-sherry.sun@nxp.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
tty: serial: fsl_lpuart: Use u32 and u8 for register variables 2025-04-10T12:44:43+00:00 Sherry Sun sherry.sun@nxp.com 2025-03-12T02:39:02+00:00 7b0b0c70de2f68c75a5da2c76c2a2856cd9847df [ Upstream commit b6a8f6ab2c53e5ea3c7f2a3978db378a89bb7595 ] Use u32 and u8 rather than unsigned long or unsigned char for register variables for clarity and consistency. Signed-off-by: Sherry Sun <sherry.sun@nxp.com> Link: https://lore.kernel.org/r/20250312023904.1343351-2-sherry.sun@nxp.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Stable-dep-of: e98ab45ec518 ("tty: serial: lpuart: only disable CTS instead of overwriting the whole UARTMODIR register") Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit b6a8f6ab2c53e5ea3c7f2a3978db378a89bb7595 ]

Use u32 and u8 rather than unsigned long or unsigned char for register
variables for clarity and consistency.

Signed-off-by: Sherry Sun <sherry.sun@nxp.com>
Link: https://lore.kernel.org/r/20250312023904.1343351-2-sherry.sun@nxp.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Stable-dep-of: e98ab45ec518 ("tty: serial: lpuart: only disable CTS instead of overwriting the whole UARTMODIR register")
Signed-off-by: Sasha Levin <sashal@kernel.org>