linux-stable.git/drivers/tty, branch linux-5.4.y Linux kernel stable tree serial: 8250_dw: handle reset control deassert error 2025-12-03T11:45:06+00:00 Artem Shimko a.shimko.dev@gmail.com 2025-10-27T19:22:45+00:00 e04a3354040944248ee80bd49c573933f6dcbd3c [ Upstream commit daeb4037adf7d3349b4a1fb792f4bc9824686a4b ] Check the return value of reset_control_deassert() in the probe function to prevent continuing probe when reset deassertion fails. Previously, reset_control_deassert() was called without checking its return value, which could lead to probe continuing even when the device reset wasn't properly deasserted. The fix checks the return value and returns an error with dev_err_probe() if reset deassertion fails, providing better error handling and diagnostics. Fixes: acbdad8dd1ab ("serial: 8250_dw: simplify optional reset handling") Cc: stable <stable@kernel.org> Signed-off-by: Artem Shimko <a.shimko.dev@gmail.com> Link: https://patch.msgid.link/20251019095131.252848-1-a.shimko.dev@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
[ Upstream commit daeb4037adf7d3349b4a1fb792f4bc9824686a4b ]

Check the return value of reset_control_deassert() in the probe
function to prevent continuing probe when reset deassertion fails.

Previously, reset_control_deassert() was called without checking its
return value, which could lead to probe continuing even when the
device reset wasn't properly deasserted.

The fix checks the return value and returns an error with dev_err_probe()
if reset deassertion fails, providing better error handling and
diagnostics.

Fixes: acbdad8dd1ab ("serial: 8250_dw: simplify optional reset handling")
Cc: stable <stable@kernel.org>
Signed-off-by: Artem Shimko <a.shimko.dev@gmail.com>
Link: https://patch.msgid.link/20251019095131.252848-1-a.shimko.dev@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
serial: 8250_dw: Use devm_add_action_or_reset() 2025-12-03T11:45:06+00:00 Andy Shevchenko andriy.shevchenko@linux.intel.com 2025-10-27T19:22:44+00:00 71e98d9b72a94cea1052bc4921a0ab711835b204 [ Upstream commit 295b09128d12fb1a7a67f771cc0ae0df869eafaf ] Slightly simplify ->probe() and drop a few goto labels by using devm_add_action_or_reset() for clock and reset cleanup. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Link: https://lore.kernel.org/r/20220509172129.37770-1-andriy.shevchenko@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Stable-dep-of: daeb4037adf7 ("serial: 8250_dw: handle reset control deassert error") Signed-off-by: Sasha Levin <sashal@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
[ Upstream commit 295b09128d12fb1a7a67f771cc0ae0df869eafaf ]

Slightly simplify ->probe() and drop a few goto labels by using
devm_add_action_or_reset() for clock and reset cleanup.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20220509172129.37770-1-andriy.shevchenko@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Stable-dep-of: daeb4037adf7 ("serial: 8250_dw: handle reset control deassert error")
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
serial: 8250_dw: Use devm_clk_get_optional() to get the input clock 2025-12-03T11:45:06+00:00 Andy Shevchenko andriy.shevchenko@linux.intel.com 2025-10-27T19:22:43+00:00 fabb861b507a6734f66a8ff90af80ad3f60f9044 [ Upstream commit a8afc193558a42d5df724c84436ae3b2446d8a30 ] Simplify the code which fetches the input clock by using devm_clk_get_optional(). This comes with a small functional change: previously all errors were ignored except deferred probe. Now all errors are treated as errors. If no input clock is present devm_clk_get_optional() will return NULL instead of an error which matches the behavior of the old code. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Link: https://lore.kernel.org/r/20190925162617.30368-1-andriy.shevchenko@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Stable-dep-of: daeb4037adf7 ("serial: 8250_dw: handle reset control deassert error") Signed-off-by: Sasha Levin <sashal@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
[ Upstream commit a8afc193558a42d5df724c84436ae3b2446d8a30 ]

Simplify the code which fetches the input clock by using
devm_clk_get_optional(). This comes with a small functional change: previously
all errors were ignored except deferred probe. Now all errors are
treated as errors. If no input clock is present devm_clk_get_optional() will
return NULL instead of an error which matches the behavior of the old code.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20190925162617.30368-1-andriy.shevchenko@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Stable-dep-of: daeb4037adf7 ("serial: 8250_dw: handle reset control deassert error")
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
serial: max310x: Add error checking in probe() 2025-10-29T12:59:47+00:00 Dan Carpenter dan.carpenter@linaro.org 2025-08-07T15:54:37+00:00 148aba0be56fc991a9e9491e0b2a9b8165c59101 [ Upstream commit 672a37ba8af1f2ebcedeb94aea2cdd047f805f30 ] Check if devm_i2c_new_dummy_device() fails. Fixes: 2e1f2d9a9bdb ("serial: max310x: implement I2C support") Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org> Link: https://lore.kernel.org/r/aJTMPZiKqeXSE-KM@stanley.mountain Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit 672a37ba8af1f2ebcedeb94aea2cdd047f805f30 ]

Check if devm_i2c_new_dummy_device() fails.

Fixes: 2e1f2d9a9bdb ("serial: max310x: implement I2C support")
Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>
Link: https://lore.kernel.org/r/aJTMPZiKqeXSE-KM@stanley.mountain
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
serial: sc16is7xx: fix bug in flow control levels init 2025-10-02T11:34:32+00:00 Hugo Villeneuve hvilleneuve@dimonoff.com 2025-09-17T13:03:19+00:00 26606c5f0be855b90171d9f2fd23281f671b7088 [ Upstream commit 535fd4c98452c87537a40610abba45daf5761ec6 ] When trying to set MCR[2], XON1 is incorrectly accessed instead. And when writing to the TCR register to configure flow control levels, we are incorrectly writing to the MSR register. The default value of $00 is then used for TCR, which means that selectable trigger levels in FCR are used in place of TCR. TCR/TLR access requires EFR[4] (enable enhanced functions) and MCR[2] to be set. EFR[4] is already set in probe(). MCR access requires LCR[7] to be zero. Since LCR is set to $BF when trying to set MCR[2], XON1 is incorrectly accessed instead because MCR shares the same address space as XON1. Since MCR[2] is unmodified and still zero, when writing to TCR we are in fact writing to MSR because TCR/TLR registers share the same address space as MSR/SPR. Fix by first removing useless reconfiguration of EFR[4] (enable enhanced functions), as it is already enabled in sc16is7xx_probe() since commit 43c51bb573aa ("sc16is7xx: make sure device is in suspend once probed"). Now LCR is $00, which means that MCR access is enabled. Also remove regcache_cache_bypass() calls since we no longer access the enhanced registers set, and TCR is already declared as volatile (in fact by declaring MSR as volatile, which shares the same address). Finally disable access to TCR/TLR registers after modifying them by clearing MCR[2]. Note: the comment about "... and internal clock div" is wrong and can be ignored/removed as access to internal clock div registers (DLL/DLH) is permitted only when LCR[7] is logic 1, not when enhanced features is enabled. And DLL/DLH access is not needed in sc16is7xx_startup(). Fixes: dfeae619d781 ("serial: sc16is7xx") Cc: stable@vger.kernel.org Signed-off-by: Hugo Villeneuve <hvilleneuve@dimonoff.com> Link: https://lore.kernel.org/r/20250731124451.1108864-1-hugo@hugovil.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> [ s->regmap renames + context ] Signed-off-by: Sasha Levin <sashal@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
[ Upstream commit 535fd4c98452c87537a40610abba45daf5761ec6 ]

When trying to set MCR[2], XON1 is incorrectly accessed instead. And when
writing to the TCR register to configure flow control levels, we are
incorrectly writing to the MSR register. The default value of $00 is then
used for TCR, which means that selectable trigger levels in FCR are used
in place of TCR.

TCR/TLR access requires EFR[4] (enable enhanced functions) and MCR[2]
to be set. EFR[4] is already set in probe().

MCR access requires LCR[7] to be zero.

Since LCR is set to $BF when trying to set MCR[2], XON1 is incorrectly
accessed instead because MCR shares the same address space as XON1.

Since MCR[2] is unmodified and still zero, when writing to TCR we are in
fact writing to MSR because TCR/TLR registers share the same address space
as MSR/SPR.

Fix by first removing useless reconfiguration of EFR[4] (enable enhanced
functions), as it is already enabled in sc16is7xx_probe() since commit
43c51bb573aa ("sc16is7xx: make sure device is in suspend once probed").
Now LCR is $00, which means that MCR access is enabled.

Also remove regcache_cache_bypass() calls since we no longer access the
enhanced registers set, and TCR is already declared as volatile (in fact
by declaring MSR as volatile, which shares the same address).

Finally disable access to TCR/TLR registers after modifying them by
clearing MCR[2].

Note: the comment about "... and internal clock div" is wrong and can be
      ignored/removed as access to internal clock div registers (DLL/DLH)
      is permitted only when LCR[7] is logic 1, not when enhanced features
      is enabled. And DLL/DLH access is not needed in sc16is7xx_startup().

Fixes: dfeae619d781 ("serial: sc16is7xx")
Cc: stable@vger.kernel.org
Signed-off-by: Hugo Villeneuve <hvilleneuve@dimonoff.com>
Link: https://lore.kernel.org/r/20250731124451.1108864-1-hugo@hugovil.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ s->regmap renames + context ]
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
tty: hvc_console: Call hvc_kick in hvc_write unconditionally 2025-10-02T11:34:28+00:00 Fabian Vogt fvogt@suse.de 2025-08-15T11:33:28+00:00 931ee3272119dbca3b674902e979d6ee78d1f463 commit cfd956dcb101aa3d25bac321fae923323a47c607 upstream. After hvc_write completes, call hvc_kick also in the case the output buffer has been drained, to ensure tty_wakeup gets called. This fixes that functions which wait for a drained buffer got stuck occasionally. Cc: stable <stable@kernel.org> Closes: https://bugzilla.opensuse.org/show_bug.cgi?id=1230062 Signed-off-by: Fabian Vogt <fvogt@suse.de> Link: https://lore.kernel.org/r/2011735.PYKUYFuaPT@fvogt-thinkpad Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit cfd956dcb101aa3d25bac321fae923323a47c607 upstream.

After hvc_write completes, call hvc_kick also in the case the output
buffer has been drained, to ensure tty_wakeup gets called.

This fixes that functions which wait for a drained buffer got stuck
occasionally.

Cc: stable <stable@kernel.org>
Closes: https://bugzilla.opensuse.org/show_bug.cgi?id=1230062
Signed-off-by: Fabian Vogt <fvogt@suse.de>
Link: https://lore.kernel.org/r/2011735.PYKUYFuaPT@fvogt-thinkpad
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
vt: defkeymap: Map keycodes above 127 to K_HOLE 2025-08-28T14:21:31+00:00 Myrrh Periwinkle myrrhperiwinkle@qtmlabs.xyz 2025-07-02T14:17:58+00:00 8526b9684b32219fea08e81c2284ccaf9bfe2b67 commit b43cb4ff85da5cf29c4cd351ef1d7dd8210780f7 upstream. The maximum number of keycodes got bumped to 256 a very long time ago, but the default keymaps were never adjusted to match. This is causing the kernel to interpret keycodes above 127 as U+0000 if the shipped generated keymap is used. Fix this by mapping all keycodes above 127 to K_HOLE so the kernel ignores them. The contents of this patche were generated by rerunning `loadkeys --mktable --unicode` and only including the changes to map keycodes above 127 to K_HOLE. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Myrrh Periwinkle <myrrhperiwinkle@qtmlabs.xyz> Cc: stable <stable@kernel.org> Reviewed-by: Jiri Slaby <jirislaby@kernel.org> Link: https://lore.kernel.org/r/20250702-vt-misc-unicode-fixes-v1-2-c27e143cc2eb@qtmlabs.xyz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit b43cb4ff85da5cf29c4cd351ef1d7dd8210780f7 upstream.

The maximum number of keycodes got bumped to 256 a very long time ago,
but the default keymaps were never adjusted to match. This is causing
the kernel to interpret keycodes above 127 as U+0000 if the shipped
generated keymap is used.

Fix this by mapping all keycodes above 127 to K_HOLE so the kernel
ignores them.

The contents of this patche were generated by rerunning `loadkeys
--mktable --unicode` and only including the changes to map keycodes
above 127 to K_HOLE.

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Myrrh Periwinkle <myrrhperiwinkle@qtmlabs.xyz>
Cc: stable <stable@kernel.org>
Reviewed-by: Jiri Slaby <jirislaby@kernel.org>
Link: https://lore.kernel.org/r/20250702-vt-misc-unicode-fixes-v1-2-c27e143cc2eb@qtmlabs.xyz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
vt: keyboard: Don't process Unicode characters in K_OFF mode 2025-08-28T14:21:30+00:00 Myrrh Periwinkle myrrhperiwinkle@qtmlabs.xyz 2025-07-02T14:17:57+00:00 4a00513483a4e0a03a3e4d5c15261dd6b72fad58 commit b1cc2092ea7a52e2c435aee6d2b1bcb773202663 upstream. We don't process Unicode characters if the virtual terminal is in raw mode, so there's no reason why we shouldn't do the same for K_OFF (especially since people would expect K_OFF to actually turn off all VT key processing). Fixes: 9fc3de9c8356 ("vt: Add virtual console keyboard mode OFF") Signed-off-by: Myrrh Periwinkle <myrrhperiwinkle@qtmlabs.xyz> Cc: stable <stable@kernel.org> Reviewed-by: Jiri Slaby <jirislaby@kernel.org> Link: https://lore.kernel.org/r/20250702-vt-misc-unicode-fixes-v1-1-c27e143cc2eb@qtmlabs.xyz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit b1cc2092ea7a52e2c435aee6d2b1bcb773202663 upstream.

We don't process Unicode characters if the virtual terminal is in raw
mode, so there's no reason why we shouldn't do the same for K_OFF
(especially since people would expect K_OFF to actually turn off all VT
key processing).

Fixes: 9fc3de9c8356 ("vt: Add virtual console keyboard mode OFF")
Signed-off-by: Myrrh Periwinkle <myrrhperiwinkle@qtmlabs.xyz>
Cc: stable <stable@kernel.org>
Reviewed-by: Jiri Slaby <jirislaby@kernel.org>
Link: https://lore.kernel.org/r/20250702-vt-misc-unicode-fixes-v1-1-c27e143cc2eb@qtmlabs.xyz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
serial: 8250: fix panic due to PSLVERR 2025-08-28T14:21:30+00:00 Yunhui Cui cuiyunhui@bytedance.com 2025-07-23T02:33:22+00:00 0b882f00655afefbc7729c6b5aec86f7a5473a3d commit 7f8fdd4dbffc05982b96caf586f77a014b2a9353 upstream. When the PSLVERR_RESP_EN parameter is set to 1, the device generates an error response if an attempt is made to read an empty RBR (Receive Buffer Register) while the FIFO is enabled. In serial8250_do_startup(), calling serial_port_out(port, UART_LCR, UART_LCR_WLEN8) triggers dw8250_check_lcr(), which invokes dw8250_force_idle() and serial8250_clear_and_reinit_fifos(). The latter function enables the FIFO via serial_out(p, UART_FCR, p->fcr). Execution proceeds to the serial_port_in(port, UART_RX). This satisfies the PSLVERR trigger condition. When another CPU (e.g., using printk()) is accessing the UART (UART is busy), the current CPU fails the check (value & ~UART_LCR_SPAR) == (lcr & ~UART_LCR_SPAR) in dw8250_check_lcr(), causing it to enter dw8250_force_idle(). Put serial_port_out(port, UART_LCR, UART_LCR_WLEN8) under the port->lock to fix this issue. Panic backtrace: [ 0.442336] Oops - unknown exception [#1] [ 0.442343] epc : dw8250_serial_in32+0x1e/0x4a [ 0.442351] ra : serial8250_do_startup+0x2c8/0x88e ... [ 0.442416] console_on_rootfs+0x26/0x70 Fixes: c49436b657d0 ("serial: 8250_dw: Improve unwritable LCR workaround") Link: https://lore.kernel.org/all/84cydt5peu.fsf@jogness.linutronix.de/T/ Signed-off-by: Yunhui Cui <cuiyunhui@bytedance.com> Reviewed-by: John Ogness <john.ogness@linutronix.de> Cc: stable <stable@kernel.org> Link: https://lore.kernel.org/r/20250723023322.464-2-cuiyunhui@bytedance.com [ Applied fix to serial8250_do_startup() instead of serial8250_initialize() ] Signed-off-by: Sasha Levin <sashal@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 7f8fdd4dbffc05982b96caf586f77a014b2a9353 upstream.

When the PSLVERR_RESP_EN parameter is set to 1, the device generates
an error response if an attempt is made to read an empty RBR (Receive
Buffer Register) while the FIFO is enabled.

In serial8250_do_startup(), calling serial_port_out(port, UART_LCR,
UART_LCR_WLEN8) triggers dw8250_check_lcr(), which invokes
dw8250_force_idle() and serial8250_clear_and_reinit_fifos(). The latter
function enables the FIFO via serial_out(p, UART_FCR, p->fcr).
Execution proceeds to the serial_port_in(port, UART_RX).
This satisfies the PSLVERR trigger condition.

When another CPU (e.g., using printk()) is accessing the UART (UART
is busy), the current CPU fails the check (value & ~UART_LCR_SPAR) ==
(lcr & ~UART_LCR_SPAR) in dw8250_check_lcr(), causing it to enter
dw8250_force_idle().

Put serial_port_out(port, UART_LCR, UART_LCR_WLEN8) under the port->lock
to fix this issue.

Panic backtrace:
[    0.442336] Oops - unknown exception [#1]
[    0.442343] epc : dw8250_serial_in32+0x1e/0x4a
[    0.442351]  ra : serial8250_do_startup+0x2c8/0x88e
...
[    0.442416] console_on_rootfs+0x26/0x70

Fixes: c49436b657d0 ("serial: 8250_dw: Improve unwritable LCR workaround")
Link: https://lore.kernel.org/all/84cydt5peu.fsf@jogness.linutronix.de/T/
Signed-off-by: Yunhui Cui <cuiyunhui@bytedance.com>
Reviewed-by: John Ogness <john.ogness@linutronix.de>
Cc: stable <stable@kernel.org>
Link: https://lore.kernel.org/r/20250723023322.464-2-cuiyunhui@bytedance.com
[ Applied fix to serial8250_do_startup() instead of serial8250_initialize() ]
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
pch_uart: Fix dma_sync_sg_for_device() nents value 2025-08-28T14:21:14+00:00 Thomas Fourier fourier.thomas@gmail.com 2025-07-01T11:34:52+00:00 fe96b632ad43841309d6bca3853107d60bd7e985 commit 6c0e9f05c9d7875995b0e92ace71be947f280bbd upstream. The dma_sync_sg_for_device() functions should be called with the same nents as the dma_map_sg(), not the value the map function returned according to the documentation in Documentation/core-api/dma-api.rst:450: With the sync_sg API, all the parameters must be the same as those passed into the sg mapping API. Fixes: da3564ee027e ("pch_uart: add multi-scatter processing") Cc: stable <stable@kernel.org> Signed-off-by: Thomas Fourier <fourier.thomas@gmail.com> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Link: https://lore.kernel.org/r/20250701113452.18590-2-fourier.thomas@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 6c0e9f05c9d7875995b0e92ace71be947f280bbd upstream.

The dma_sync_sg_for_device() functions should be called with the same
nents as the dma_map_sg(), not the value the map function returned
according to the documentation in Documentation/core-api/dma-api.rst:450:
	With the sync_sg API, all the parameters must be the same
	as those passed into the sg mapping API.

Fixes: da3564ee027e ("pch_uart: add multi-scatter processing")
Cc: stable <stable@kernel.org>
Signed-off-by: Thomas Fourier <fourier.thomas@gmail.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20250701113452.18590-2-fourier.thomas@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>