Hi Sakari,
Thank you for the patch.
On Wed, Apr 10, 2024 at 02:47:12PM +0300, Sakari Ailus wrote:
> Turn on the privacy LED only if streamon succeeds. This can be done after
> enabling streaming on the sensor.
>
> Fixes: b6e10ff6c23d ("media: v4l2-core: Make the v4l2-core code enable/disable the privacy LED if present")
> Signed-off-by: Sakari Ailus <sakari.ailus@xxxxxxxxxxxxxxx>
> ---
> drivers/media/v4l2-core/v4l2-subdev.c | 22 ++++++++++++----------
> 1 file changed, 12 insertions(+), 10 deletions(-)
>
> diff --git a/drivers/media/v4l2-core/v4l2-subdev.c b/drivers/media/v4l2-core/v4l2-subdev.c
> index 4c6198c48dd6..012b757eac9f 100644
> --- a/drivers/media/v4l2-core/v4l2-subdev.c
> +++ b/drivers/media/v4l2-core/v4l2-subdev.c
> @@ -412,15 +412,6 @@ static int call_s_stream(struct v4l2_subdev *sd, int enable)
> if (WARN_ON(!!sd->enabled_streams == !!enable))
> return 0;
>
> -#if IS_REACHABLE(CONFIG_LEDS_CLASS)
> - if (!IS_ERR_OR_NULL(sd->privacy_led)) {
> - if (enable)
> - led_set_brightness(sd->privacy_led,
> - sd->privacy_led->max_brightness);
> - else
> - led_set_brightness(sd->privacy_led, 0);
> - }
> -#endif
> ret = sd->ops->video->s_stream(sd, enable);
>
> if (!enable && ret < 0) {
> @@ -428,9 +419,20 @@ static int call_s_stream(struct v4l2_subdev *sd, int enable)
> ret = 0;
> }
>
> - if (!ret)
> + if (!ret) {
> sd->enabled_streams = enable ? BIT(0) : 0;
>
> +#if IS_REACHABLE(CONFIG_LEDS_CLASS)
> + if (!IS_ERR_OR_NULL(sd->privacy_led)) {
> + if (enable)
> + led_set_brightness(sd->privacy_led,
> + sd->privacy_led->max_brightness);
> + else
> + led_set_brightness(sd->privacy_led, 0);
> + }
> +#endif
This means that the LED will be turned slightly after the camera is
enabled. I don't think it's an issue in practice. Another possibly more
important concern is that we should maybe check the return value of
led_set_brightness(), and fail .s_stream() when we can't enable the
privacy LED at stream on time. In that case, it would be best to keep
turning the privacy LED on before calling .s_stream(). It should still
be turned off only after calling .s_stream() though.
> + }
> +
> return ret;
> }
>
--
Regards,
Laurent Pinchart
