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.
Regards,
Hans
>
>>
>>>
>>> Which then cleans up nicely by Tomi's patch
>>> introducing the privacy LED helper functions,
>>> to something like this:
>>>
>>> if (!ret {
>>> if (enable) {
>>> sd->enabled_streams = BIT(0);
>>> v4l2_subdev_enable_privacy_led(sd);
>>> } else {
>>> sd->enabled_streams = 0;
>>> v4l2_subdev_disable_privacy_led(sd);
>>> }
>>> }
>>>
>>
>
