| Message ID | 20240410114712.661186-1-sakari.ailus@linux.intel.com |
|---|---|
| State | Superseded |
| Headers | show |
| Series | [v2,1/1] media: v4l: Don't turn on privacy LED if streamon fails | expand |
Hi Laurent, On Fri, Apr 12, 2024 at 08:46:21PM +0300, Laurent Pinchart wrote: > 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@linux.intel.com> > > --- > > 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 That's what I'd think as well. Typically even the exposure time is much, much longer than what it takes to get here. > 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. The return type of led_set_brightness() is void. Maybe because a large majority is GPIO-controlled?
On Mon, Apr 15, 2024 at 07:29:41AM +0000, Sakari Ailus wrote: > On Mon, Apr 15, 2024 at 10:18:12AM +0300, Laurent Pinchart wrote: > > > Maybe because a large majority is GPIO-controlled? > > > > GPIOs can fail, in particular when they're on I2C GPIO expanders. > > Sure, but gpiod_set_value() return type is also void. I know, so there's nothing we can do short term. > It just works... right? Until it doesn't :-)
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 + } + return ret; }
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@linux.intel.com> --- drivers/media/v4l2-core/v4l2-subdev.c | 22 ++++++++++++---------- 1 file changed, 12 insertions(+), 10 deletions(-)