The note in c2adda27d202f ("video: backlight: Add of_find_backlight helper in backlight.c") says that gpio-backlight uses brightness as power state. This has been fixed since in ec665b756e6f7 ("backlight: gpio-backlight: Correct initial power state handling") and other backlight drivers do not require this workaround. Drop the workaround.
This fixes the case where e.g. pwm-backlight can perfectly well be set to brightness 0 on boot in DT, which without this patch leads to the display brightness to be max instead of off.
Fixes: c2adda27d202f ("video: backlight: Add of_find_backlight helper in backlight.c") Signed-off-by: Marek Vasut marex@denx.de Cc: Daniel Thompson daniel.thompson@linaro.org Cc: Meghana Madhyastha meghana.madhyastha@gmail.com Cc: Noralf Trønnes noralf@tronnes.org Cc: Sean Paul seanpaul@chromium.org Cc: Thierry Reding treding@nvidia.com --- drivers/video/backlight/backlight.c | 6 ------ 1 file changed, 6 deletions(-)
diff --git a/drivers/video/backlight/backlight.c b/drivers/video/backlight/backlight.c index 537fe1b376ad7..fc990e576340b 100644 --- a/drivers/video/backlight/backlight.c +++ b/drivers/video/backlight/backlight.c @@ -688,12 +688,6 @@ static struct backlight_device *of_find_backlight(struct device *dev) of_node_put(np); if (!bd) return ERR_PTR(-EPROBE_DEFER); - /* - * Note: gpio_backlight uses brightness as - * power state during probe - */ - if (!bd->props.brightness) - bd->props.brightness = bd->props.max_brightness; } }
Den 09.07.2021 15.26, skrev Marek Vasut:
The note in c2adda27d202f ("video: backlight: Add of_find_backlight helper in backlight.c") says that gpio-backlight uses brightness as power state. This has been fixed since in ec665b756e6f7 ("backlight: gpio-backlight: Correct initial power state handling") and other backlight drivers do not require this workaround. Drop the workaround.
This fixes the case where e.g. pwm-backlight can perfectly well be set to brightness 0 on boot in DT, which without this patch leads to the display brightness to be max instead of off.
Fixes: c2adda27d202f ("video: backlight: Add of_find_backlight helper in backlight.c")
I not sure about the rules, but if this is automatically picked up for stable, maybe this is needed to avoid changing behaviour on 4.19:
Cc: stable@vger.kernel.org # 5.4+
of_find_backlight() was added in 4.17 and the gpio fix in 5.4.
Or perhaps there are other ways to signal this dependency.
Signed-off-by: Marek Vasut marex@denx.de Cc: Daniel Thompson daniel.thompson@linaro.org Cc: Meghana Madhyastha meghana.madhyastha@gmail.com Cc: Noralf Trønnes noralf@tronnes.org Cc: Sean Paul seanpaul@chromium.org Cc: Thierry Reding treding@nvidia.com
Acked-by: Noralf Trønnes noralf@tronnes.org
On Fri, Jul 09, 2021 at 03:53:16PM +0200, Noralf Trønnes wrote:
Den 09.07.2021 15.26, skrev Marek Vasut:
The note in c2adda27d202f ("video: backlight: Add of_find_backlight helper in backlight.c") says that gpio-backlight uses brightness as power state. This has been fixed since in ec665b756e6f7 ("backlight: gpio-backlight: Correct initial power state handling") and other backlight drivers do not require this workaround. Drop the workaround.
This fixes the case where e.g. pwm-backlight can perfectly well be set to brightness 0 on boot in DT, which without this patch leads to the display brightness to be max instead of off.
Fixes: c2adda27d202f ("video: backlight: Add of_find_backlight helper in backlight.c")
I not sure about the rules, but if this is automatically picked up for stable, maybe this is needed to avoid changing behaviour on 4.19:
of_find_backlight() was added in 4.17 and the gpio fix in 5.4.
Or perhaps there are other ways to signal this dependency.
Agree we need to make sure the Fixes: tag doesn't provoke regressions in v4.19.
Is this the syntax appropriate?
Cc: stable@vger.kernel.org # 5.4+ Cc: stable@vger.kernel.org # 4.19.x: ec665b756e6f7: backlight: gpio-backlight: Correct initial power state handling
Signed-off-by: Marek Vasut marex@denx.de Cc: Daniel Thompson daniel.thompson@linaro.org Cc: Meghana Madhyastha meghana.madhyastha@gmail.com Cc: Noralf Trønnes noralf@tronnes.org Cc: Sean Paul seanpaul@chromium.org Cc: Thierry Reding treding@nvidia.com
Acked-by: Noralf Trønnes noralf@tronnes.org
With the above (or something similar to avoid problems with v4.19): Reviewed-by: Daniel Thompson daniel.thompson@linaro.org
Daniel.
dri-devel@lists.freedesktop.org
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Daniel Thompson -
Marek Vasut -
Noralf Trønnes