On Wed, Apr 10, 2024 at 01:37:13PM +0200, Hans de Goede wrote:
> Hi,
>
> On 4/10/24 1:35 PM, Sakari Ailus wrote:
> > On Wed, Apr 10, 2024 at 11:31:48AM +0000, Sakari Ailus wrote:
> >> Hi Hans,
> >>
> >> Thanks for the review.
> >>
> >> On Wed, Apr 10, 2024 at 12:12:33PM +0200, Hans de Goede wrote:
> >>> Hi Sakari,
> >>>
> >>> Thank you for fixing this.
> >>>
> >>> On 4/10/24 12:03 PM, 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 | 19 ++++++++++---------
> >>>> 1 file changed, 10 insertions(+), 9 deletions(-)
> >>>>
> >>>> diff --git a/drivers/media/v4l2-core/v4l2-subdev.c b/drivers/media/v4l2-core/v4l2-subdev.c
> >>>> index 4c6198c48dd6..acb7c3003ab6 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) {
> >>>> @@ -431,6 +422,16 @@ static int call_s_stream(struct v4l2_subdev *sd, int enable)
> >>>> if (!ret)
> >>>> sd->enabled_streams = enable ? BIT(0) : 0;
> >>>>
> >>>> +#if IS_REACHABLE(CONFIG_LEDS_CLASS)
> >>>> + if (!IS_ERR_OR_NULL(sd->privacy_led) && !(enable && ret < 0)) {
> >>>
> >>> There already is a:
> >>>
> >>> if (!enable && ret < 0)
> >>> ret = 0;
> >>>
> >>> block above to ignore stream-off errors, so you can just test for:
> >>>
> >>> if (!ret && !IS_ERR_OR_NULL(sd->privacy_led)) {
> >>> ...
> >>> }
> >>>
> >>> And then you can move the whole block to inside the existing:
> >>>
> >>> if (!ret)
> >>> sd->enabled_streams = enable ? BIT(0) : 0;
> >>>
> >>> block, so you get something like this:
> >>>
> >>> 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
> >>> }
> >>
> >> Seems reasonable, I'll send v2.
> >
> > I was a bit too fast to hit y. ret will be non-zero if streamon fails
> > (enable non-zero), in which case the LED needs to be turned off. So you
> > can't have !ret condition for all LED control.
>
> But if stream-on fails then AFAICT the LED was never turned on in the first
> place. stream on / off calls must always be balanced, right ?
>
> IOW stream-on is not supposed to get called if the device is already
> streaming and if the device is not already streaming then the LED will
> already be off.
Ah, right. I missed that part. I'll send v2 after all. :-)
--
Sakari Ailus
