linux.git/drivers/video/backlight, branch v6.12.80

backlight: qcom-wled: Change PM8950 WLED configurations

2026-03-04T12:20:33+00:00

[ Upstream commit 83333aa97441ba7ce32b91e8a007c72d316a1c67 ]

PMI8950 WLED needs same configurations as PMI8994 WLED.

Fixes: 10258bf4534b ("backlight: qcom-wled: Add PMI8950 compatible")
Signed-off-by: Barnabás Czémán 
Reviewed-by: Konrad Dybcio 
Reviewed-by: Daniel Thompson (RISCstar) 
Link: https://patch.msgid.link/20260116-pmi8950-wled-v3-4-e6c93de84079@mainlining.org
Signed-off-by: Lee Jones 
Signed-off-by: Sasha Levin

backlight: qcom-wled: Support ovp values for PMI8994

2026-03-04T12:20:33+00:00

[ Upstream commit f29f972a6e7e3f187ea4d89b98a76c1981ca4d53 ]

WLED4 found in PMI8994 supports different ovp values.

Fixes: 6fc632d3e3e0 ("video: backlight: qcom-wled: Add PMI8994 compatible")
Signed-off-by: Barnabás Czémán 
Reviewed-by: Konrad Dybcio 
Reviewed-by: Daniel Thompson (RISCstar) 
Link: https://patch.msgid.link/20260116-pmi8950-wled-v3-2-e6c93de84079@mainlining.org
Signed-off-by: Lee Jones 
Signed-off-by: Sasha Levin

backlight: led-bl: Add devlink to supplier LEDs

2025-12-18T12:55:07+00:00

[ Upstream commit 9341d6698f4cfdfc374fb6944158d111ebe16a9d ]

LED Backlight is a consumer of one or multiple LED class devices, but
devlink is currently unable to create correct supplier-producer links when
the supplier is a class device. It creates instead a link where the
supplier is the parent of the expected device.

One consequence is that removal order is not correctly enforced.

Issues happen for example with the following sections in a device tree
overlay:

    // An LED driver chip
    pca9632@62 {
        compatible = "nxp,pca9632";
        reg = <0x62>;

	// ...

        addon_led_pwm: led-pwm@3 {
            reg = <3>;
            label = "addon:led:pwm";
        };
    };

    backlight-addon {
        compatible = "led-backlight";
        leds = <&addon_led_pwm>;
        brightness-levels = <255>;
        default-brightness-level = <255>;
    };

In this example, the devlink should be created between the backlight-addon
(consumer) and the pca9632@62 (supplier). Instead it is created between the
backlight-addon (consumer) and the parent of the pca9632@62, which is
typically the I2C bus adapter.

On removal of the above overlay, the LED driver can be removed before the
backlight device, resulting in:

    Unable to handle kernel NULL pointer dereference at virtual address 0000000000000010
    ...
    Call trace:
     led_put+0xe0/0x140
     devm_led_release+0x6c/0x98

Another way to reproduce the bug without any device tree overlays is
unbinding the LED class device (pca9632@62) before unbinding the consumer
(backlight-addon):

  echo 11-0062 >/sys/bus/i2c/drivers/leds-pca963x/unbind
  echo ...backlight-dock >/sys/bus/platform/drivers/led-backlight/unbind

Fix by adding a devlink between the consuming led-backlight device and the
supplying LED device, as other drivers and subsystems do as well.

Fixes: ae232e45acf9 ("backlight: add led-backlight driver")
Signed-off-by: Luca Ceresoli 
Reviewed-by: Daniel Thompson (RISCstar) 
Reviewed-by: Herve Codina 
Tested-by: Alexander Sverdlin 
Link: https://patch.msgid.link/20250519-led-backlight-add-devlink-to-supplier-class-device-v6-1-845224aeb2ce@bootlin.com
Signed-off-by: Lee Jones 
Signed-off-by: Sasha Levin

video: backlight: lp855x_bl: Set correct EPROM start for LP8556

2025-11-13T20:34:06+00:00

[ Upstream commit 07c7efda24453e05951fb2879f5452b720b91169 ]

According to LP8556 datasheet EPROM region starts at 0x98 so adjust value
in the driver accordingly.

Signed-off-by: Svyatoslav Ryhel 
Reviewed-by: "Daniel Thompson (RISCstar)" 
Link: https://lore.kernel.org/r/20250909074304.92135-2-clamor95@gmail.com
Signed-off-by: Lee Jones 
Signed-off-by: Sasha Levin

backlight: pm8941: Add NULL check in wled_configure()

2025-06-19T13:32:04+00:00

[ Upstream commit e12d3e1624a02706cdd3628bbf5668827214fa33 ]

devm_kasprintf() returns NULL when memory allocation fails. Currently,
wled_configure() does not check for this case, which results in a NULL
pointer dereference.

Add NULL check after devm_kasprintf() to prevent this issue.

Fixes: f86b77583d88 ("backlight: pm8941: Convert to using %pOFn instead of device_node.name")
Signed-off-by: Henry Martin 
Reviewed-by: Dmitry Baryshkov 
Reviewed-by: "Daniel Thompson (RISCstar)" 
Link: https://lore.kernel.org/r/20250401091647.22784-1-bsdhenrymartin@gmail.com
Signed-off-by: Lee Jones 
Signed-off-by: Sasha Levin

backlight: led_bl: Hold led_access lock when calling led_sysfs_disable()

2025-04-20T08:15:46+00:00

commit 276822a00db3c1061382b41e72cafc09d6a0ec30 upstream.

Lockdep detects the following issue on led-backlight removal:
  [  142.315935] ------------[ cut here ]------------
  [  142.315954] WARNING: CPU: 2 PID: 292 at drivers/leds/led-core.c:455 led_sysfs_enable+0x54/0x80
  ...
  [  142.500725] Call trace:
  [  142.503176]  led_sysfs_enable+0x54/0x80 (P)
  [  142.507370]  led_bl_remove+0x80/0xa8 [led_bl]
  [  142.511742]  platform_remove+0x30/0x58
  [  142.515501]  device_remove+0x54/0x90
  ...

Indeed, led_sysfs_enable() has to be called with the led_access
lock held.

Hold the lock when calling led_sysfs_disable().

Fixes: ae232e45acf9 ("backlight: add led-backlight driver")
Cc: stable@vger.kernel.org
Signed-off-by: Herve Codina 
Link: https://lore.kernel.org/r/20250122091914.309533-1-herve.codina@bootlin.com
Signed-off-by: Lee Jones 
Signed-off-by: Greg Kroah-Hartman

backlight: l4f00242t03: Add check for spi_setup

2024-08-01T12:40:14+00:00

Add check for the return value of spi_setup() and return the error
if it fails in order to catch the error.

Signed-off-by: Chen Ni 
Reviewed-by: Daniel Thompson 
Link: https://lore.kernel.org/r/20240705092800.3221159-1-nichen@iscas.ac.cn
Signed-off-by: Lee Jones

backlight: sky81452-backlight: Use backlight power constants

2024-07-04T15:45:25+00:00

Replace FB_BLANK_ constants with their counterparts from the
backlight subsystem. The values are identical, so there's no
change in functionality.

Signed-off-by: Thomas Zimmermann 
Reviewed-by: Daniel Thompson 
Link: https://lore.kernel.org/r/20240624152033.25016-18-tzimmermann@suse.de
Signed-off-by: Lee Jones

backlight: rave-sp-backlight: Use backlight power constants

2024-07-04T15:45:25+00:00

Replace FB_BLANK_ constants with their counterparts from the
backlight subsystem. The values are identical, so there's no
change in functionality.

Signed-off-by: Thomas Zimmermann 
Reviewed-by: Daniel Thompson 
Link: https://lore.kernel.org/r/20240624152033.25016-17-tzimmermann@suse.de
Signed-off-by: Lee Jones

backlight: pwm-backlight: Use backlight power constants

2024-07-04T15:45:25+00:00

Replace FB_BLANK_ constants with their counterparts from the
backlight subsystem. The values are identical, so there's no
change in functionality.

Signed-off-by: Thomas Zimmermann 
Reviewed-by: Daniel Thompson 
Link: https://lore.kernel.org/r/20240624152033.25016-16-tzimmermann@suse.de
Signed-off-by: Lee Jones