The patch below does not apply to the 5.15-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.

To reproduce the conflict and resubmit, you may use the following commands:

git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.15.y git checkout FETCH_HEAD git cherry-pick -x 276822a00db3c1061382b41e72cafc09d6a0ec30 # <resolve conflicts, build, test, etc.> git commit -s git send-email --to 'stable@vger.kernel.org' --in-reply-to '2025041744-kite-tasty-461a@gregkh' --subject-prefix 'PATCH 5.15.y' HEAD^..

Possible dependencies:

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From 276822a00db3c1061382b41e72cafc09d6a0ec30 Mon Sep 17 00:00:00 2001 From: Herve Codina herve.codina@bootlin.com Date: Wed, 22 Jan 2025 10:19:14 +0100 Subject: [PATCH] backlight: led_bl: Hold led_access lock when calling led_sysfs_disable()

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 herve.codina@bootlin.com Link: https://lore.kernel.org/r/20250122091914.309533-1-herve.codina@bootlin.com Signed-off-by: Lee Jones lee@kernel.org

diff --git a/drivers/video/backlight/led_bl.c b/drivers/video/backlight/led_bl.c index ae34d1ecbfbe..d2db157b2c29 100644 --- a/drivers/video/backlight/led_bl.c +++ b/drivers/video/backlight/led_bl.c @@ -229,8 +229,11 @@ static void led_bl_remove(struct platform_device *pdev) backlight_device_unregister(bl);

led_bl_power_off(priv); - for (i = 0; i < priv->nb_leds; i++) + for (i = 0; i < priv->nb_leds; i++) { + mutex_lock(&priv->leds[i]->led_access); led_sysfs_enable(priv->leds[i]); + mutex_unlock(&priv->leds[i]->led_access); + } }

static const struct of_device_id led_bl_of_match[] = {