From: ChiYuan Huang cy_huang@richtek.com
To make sure LED enter off state after file handle is closed, initiatively configure LED_MODE to NONE. This can guarantee whatever the previous state is torch or strobe mode, the final state will be off.
Cc: stable@vger.kernel.org Fixes : 42bd6f59ae90 ("media: Add registration helpers for V4L2 flash sub-devices") Reported-by: Roger Wang roger-hy.wang@mediatek.com Signed-off-by: ChiYuan Huang cy_huang@richtek.com --- Hi, We encounter an issue. When the upper layer camera process is crashed, if the new process did not reinit the LED, it will keeps the previous state whatever it's in torch or strobe mode
OS will handle the resource management. So when the process is crashed or terminated, the 'close' API will be called to release resources. That's why we add the initiative action to trigger LED off in file handle close is called. --- drivers/media/v4l2-core/v4l2-flash-led-class.c | 6 ++++++ 1 file changed, 6 insertions(+)
diff --git a/drivers/media/v4l2-core/v4l2-flash-led-class.c b/drivers/media/v4l2-core/v4l2-flash-led-class.c index 355595a0fefa..347b37f3ef69 100644 --- a/drivers/media/v4l2-core/v4l2-flash-led-class.c +++ b/drivers/media/v4l2-core/v4l2-flash-led-class.c @@ -623,6 +623,12 @@ static int v4l2_flash_close(struct v4l2_subdev *sd, struct v4l2_subdev_fh *fh) return 0;
if (led_cdev) { + /* If file handle is released, make sure LED enter off state */ + ret = v4l2_ctrl_s_ctrl(v4l2_flash->ctrls[LED_MODE], + V4L2_FLASH_LED_MODE_NONE); + if (ret) + return ret; + mutex_lock(&led_cdev->led_access);
if (v4l2_flash->ctrls[STROBE_SOURCE])