Re: [PATCH v2 12/12] media: flash: use led_set_brightness_sync for torch brightness

From: Jacek Anaszewski
Date: Tue Sep 29 2015 - 03:26:52 EST

Hi Pavel,

Thanks for the review.

On 09/28/2015 10:37 PM, Pavel Machek wrote:
On Mon 2015-09-28 15:07:21, Jacek Anaszewski wrote:
LED subsystem shifted responsibility for choosing between SYNC or ASYNC
way of setting brightness from drivers to the caller. Adapt the wrapper
to those changes.

Umm. Maybe right patch, but wrong position in the queue, no?

If I understand changelog correctly, LED flashes will be subtly broken
before this patch is applied.

I guess this patch should be moved sooner so everything works at each
position in bisect...?

Moving it wouldn't improve anything. It would have to be merged with
patch 7/12 [1]. However, as you mentioned, LED flashes before this
patch will be broken only subtly, i.e. torch brightness will be set
from a work queue task and not synchronously. It would be barely
noticeable. Nonetheless, I can merge the patches in the next
version of the patch set.


Best regards,

Signed-off-by: Jacek Anaszewski <j.anaszewski@xxxxxxxxxxx>
Cc: Sakari Ailus <sakari.ailus@xxxxxxxxxxxxxxx>
Cc: Pavel Machek <pavel@xxxxxx>
Cc: linux-media@xxxxxxxxxxxxxxx
drivers/media/v4l2-core/v4l2-flash-led-class.c | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/media/v4l2-core/v4l2-flash-led-class.c b/drivers/media/v4l2-core/v4l2-flash-led-class.c
index 5bdfb8d..5d67335 100644
--- a/drivers/media/v4l2-core/v4l2-flash-led-class.c
+++ b/drivers/media/v4l2-core/v4l2-flash-led-class.c
@@ -107,10 +107,10 @@ static void v4l2_flash_set_led_brightness(struct v4l2_flash *v4l2_flash,
if (ctrls[LED_MODE]->val != V4L2_FLASH_LED_MODE_TORCH)

- led_set_brightness(&v4l2_flash->fled_cdev->led_cdev,
+ led_set_brightness_sync(&v4l2_flash->fled_cdev->led_cdev,
} else {
- led_set_brightness(&v4l2_flash->iled_cdev->led_cdev,
+ led_set_brightness_sync(&v4l2_flash->iled_cdev->led_cdev,
@@ -206,11 +206,11 @@ static int v4l2_flash_s_ctrl(struct v4l2_ctrl *c)
switch (c->val) {
- led_set_brightness(led_cdev, LED_OFF);
+ led_set_brightness_sync(led_cdev, LED_OFF);
return led_set_flash_strobe(fled_cdev, false);
/* Turn the torch LED off */
- led_set_brightness(led_cdev, LED_OFF);
+ led_set_brightness_sync(led_cdev, LED_OFF);
if (ctrls[STROBE_SOURCE]) {
external_strobe = (ctrls[STROBE_SOURCE]->val ==

Best Regards,
Jacek Anaszewski
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