This is a note to let you know that I've just added the patch titled video: backlight: Drop maximum brightness override for brightness zero to the 4.19-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: video-backlight-drop-maximum-brightness-override-for-brightness-zero.patch and it can be found in the queue-4.19 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From 33a5471f8da976bf271a1ebbd6b9d163cb0cb6aa Mon Sep 17 00:00:00 2001 From: Marek Vasut <marex@xxxxxxx> Date: Tue, 21 Sep 2021 19:35:06 +0200 Subject: video: backlight: Drop maximum brightness override for brightness zero MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit From: Marek Vasut <marex@xxxxxxx> commit 33a5471f8da976bf271a1ebbd6b9d163cb0cb6aa upstream. 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") Cc: <stable@xxxxxxxxxxxxxxx> # 5.4+ Cc: <stable@xxxxxxxxxxxxxxx> # 4.19.x: ec665b756e6f7: backlight: gpio-backlight: Correct initial power state handling Signed-off-by: Marek Vasut <marex@xxxxxxx> Acked-by: Noralf Trønnes <noralf@xxxxxxxxxxx> Reviewed-by: Daniel Thompson <daniel.thompson@xxxxxxxxxx> Signed-off-by: Lee Jones <lee.jones@xxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/video/backlight/backlight.c | 6 ------ 1 file changed, 6 deletions(-) --- a/drivers/video/backlight/backlight.c +++ b/drivers/video/backlight/backlight.c @@ -610,12 +610,6 @@ struct backlight_device *of_find_backlig 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; } } Patches currently in stable-queue which might be from marex@xxxxxxx are queue-4.19/rsi-fix-module-dev_oper_mode-parameter-description.patch queue-4.19/video-backlight-drop-maximum-brightness-override-for-brightness-zero.patch