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 --- drivers/video/backlight/led_bl.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-)
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[] = {