diff mbox series

[v2,1/9] media: subdev: Add privacy led helpers

Message ID 20240405-enable-streams-impro-v2-1-22bca967665d@ideasonboard.com (mailing list archive)
State Superseded
Headers
Series media: subdev: Improve stream enable/disable machinery |

Commit Message

Tomi Valkeinen April 5, 2024, 9:14 a.m. UTC 
  Add helper functions to enable and disable the privacy led. This moves
the #if from the call site to the privacy led functions, and makes
adding privacy led support to v4l2_subdev_enable/disable_streams()
cleaner.

Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
---
 drivers/media/v4l2-core/v4l2-subdev.c | 31 ++++++++++++++++++++++---------
 1 file changed, 22 insertions(+), 9 deletions(-)

Comments

Sakari Ailus April 10, 2024, 9:07 a.m. UTC | #1 
Moi,

On Fri, Apr 05, 2024 at 12:14:19PM +0300, Tomi Valkeinen wrote:
> Add helper functions to enable and disable the privacy led. This moves
> the #if from the call site to the privacy led functions, and makes
> adding privacy led support to v4l2_subdev_enable/disable_streams()
> cleaner.
> 
> Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
> ---
>  drivers/media/v4l2-core/v4l2-subdev.c | 31 ++++++++++++++++++++++---------
>  1 file changed, 22 insertions(+), 9 deletions(-)
> 
> diff --git a/drivers/media/v4l2-core/v4l2-subdev.c b/drivers/media/v4l2-core/v4l2-subdev.c
> index 4c6198c48dd6..942c7a644033 100644
> --- a/drivers/media/v4l2-core/v4l2-subdev.c
> +++ b/drivers/media/v4l2-core/v4l2-subdev.c
> @@ -148,6 +148,23 @@ static int subdev_close(struct file *file)
>  }
>  #endif /* CONFIG_VIDEO_V4L2_SUBDEV_API */
>  
> +static void v4l2_subdev_enable_privacy_led(struct v4l2_subdev *sd)
> +{
> +#if IS_REACHABLE(CONFIG_LEDS_CLASS)
> +	if (!IS_ERR_OR_NULL(sd->privacy_led))
> +		led_set_brightness(sd->privacy_led,
> +				   sd->privacy_led->max_brightness);
> +#endif
> +}
> +
> +static void v4l2_subdev_disable_privacy_led(struct v4l2_subdev *sd)
> +{
> +#if IS_REACHABLE(CONFIG_LEDS_CLASS)
> +	if (!IS_ERR_OR_NULL(sd->privacy_led))
> +		led_set_brightness(sd->privacy_led, 0);
> +#endif
> +}
> +
>  static inline int check_which(u32 which)
>  {
>  	if (which != V4L2_SUBDEV_FORMAT_TRY &&
> @@ -412,15 +429,11 @@ 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
> +	if (enable)
> +		v4l2_subdev_enable_privacy_led(sd);
> +	else
> +		v4l2_subdev_disable_privacy_led(sd);
> +
>  	ret = sd->ops->video->s_stream(sd, enable);

I see that you're only making changes before the s_stream call which also
reveals a bug here: if streaming on fails, the LED will remain lit. It
should be fixed before this set.

I cc'd Hans de Goede.

>  
>  	if (!enable && ret < 0) {
>
Hans de Goede April 10, 2024, 9:27 a.m. UTC | #2 
Hi,

On 4/10/24 11:07 AM, Sakari Ailus wrote:
> Moi,
> 
> On Fri, Apr 05, 2024 at 12:14:19PM +0300, Tomi Valkeinen wrote:
>> Add helper functions to enable and disable the privacy led. This moves
>> the #if from the call site to the privacy led functions, and makes
>> adding privacy led support to v4l2_subdev_enable/disable_streams()
>> cleaner.
>>
>> Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
>> ---
>>  drivers/media/v4l2-core/v4l2-subdev.c | 31 ++++++++++++++++++++++---------
>>  1 file changed, 22 insertions(+), 9 deletions(-)
>>
>> diff --git a/drivers/media/v4l2-core/v4l2-subdev.c b/drivers/media/v4l2-core/v4l2-subdev.c
>> index 4c6198c48dd6..942c7a644033 100644
>> --- a/drivers/media/v4l2-core/v4l2-subdev.c
>> +++ b/drivers/media/v4l2-core/v4l2-subdev.c
>> @@ -148,6 +148,23 @@ static int subdev_close(struct file *file)
>>  }
>>  #endif /* CONFIG_VIDEO_V4L2_SUBDEV_API */
>>  
>> +static void v4l2_subdev_enable_privacy_led(struct v4l2_subdev *sd)
>> +{
>> +#if IS_REACHABLE(CONFIG_LEDS_CLASS)
>> +	if (!IS_ERR_OR_NULL(sd->privacy_led))
>> +		led_set_brightness(sd->privacy_led,
>> +				   sd->privacy_led->max_brightness);
>> +#endif
>> +}
>> +
>> +static void v4l2_subdev_disable_privacy_led(struct v4l2_subdev *sd)
>> +{
>> +#if IS_REACHABLE(CONFIG_LEDS_CLASS)
>> +	if (!IS_ERR_OR_NULL(sd->privacy_led))
>> +		led_set_brightness(sd->privacy_led, 0);
>> +#endif
>> +}
>> +
>>  static inline int check_which(u32 which)
>>  {
>>  	if (which != V4L2_SUBDEV_FORMAT_TRY &&
>> @@ -412,15 +429,11 @@ 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
>> +	if (enable)
>> +		v4l2_subdev_enable_privacy_led(sd);
>> +	else
>> +		v4l2_subdev_disable_privacy_led(sd);
>> +
>>  	ret = sd->ops->video->s_stream(sd, enable);
> 
> I see that you're only making changes before the s_stream call which also
> reveals a bug here: if streaming on fails, the LED will remain lit. It
> should be fixed before this set.
> 
> I cc'd Hans de Goede.

Right that seems like a bug which I introduced. I think it would be
best to move the setting of the LED on/off to after the s_stream()
call in the:

       if (!ret)
                sd->enabled_streams = enable ? BIT(0) : 0;

block, so that the LED is not touched when s_stream(sd, 1) fails.

This delay enabling the LED slightly on stream start but IMHO
that is not a bit issue.

Regards,

Hans
diff mbox series

Patch

diff --git a/drivers/media/v4l2-core/v4l2-subdev.c b/drivers/media/v4l2-core/v4l2-subdev.c
index 4c6198c48dd6..942c7a644033 100644
--- a/drivers/media/v4l2-core/v4l2-subdev.c
+++ b/drivers/media/v4l2-core/v4l2-subdev.c
@@ -148,6 +148,23 @@  static int subdev_close(struct file *file)
 }
 #endif /* CONFIG_VIDEO_V4L2_SUBDEV_API */
 
+static void v4l2_subdev_enable_privacy_led(struct v4l2_subdev *sd)
+{
+#if IS_REACHABLE(CONFIG_LEDS_CLASS)
+	if (!IS_ERR_OR_NULL(sd->privacy_led))
+		led_set_brightness(sd->privacy_led,
+				   sd->privacy_led->max_brightness);
+#endif
+}
+
+static void v4l2_subdev_disable_privacy_led(struct v4l2_subdev *sd)
+{
+#if IS_REACHABLE(CONFIG_LEDS_CLASS)
+	if (!IS_ERR_OR_NULL(sd->privacy_led))
+		led_set_brightness(sd->privacy_led, 0);
+#endif
+}
+
 static inline int check_which(u32 which)
 {
 	if (which != V4L2_SUBDEV_FORMAT_TRY &&
@@ -412,15 +429,11 @@  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
+	if (enable)
+		v4l2_subdev_enable_privacy_led(sd);
+	else
+		v4l2_subdev_disable_privacy_led(sd);
+
 	ret = sd->ops->video->s_stream(sd, enable);
 
 	if (!enable && ret < 0) {