linux-kernel - Re: [PATCH v2 7/9] media: subdev: Support privacy led in v4l2_subdev_enable/disable

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Message-ID: <ZhZl0Se7I5eeQfW8@kekkonen.localdomain>
Date: Wed, 10 Apr 2024 10:11:29 +0000
From: Sakari Ailus <sakari.ailus@...ux.intel.com>
To: Tomi Valkeinen <tomi.valkeinen@...asonboard.com>
Cc: Mauro Carvalho Chehab <mchehab@...nel.org>,
	Hans Verkuil <hverkuil@...all.nl>,
	Laurent Pinchart <laurent.pinchart@...asonboard.com>,
	Umang Jain <umang.jain@...asonboard.com>,
	linux-media@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH v2 7/9] media: subdev: Support privacy led in
 v4l2_subdev_enable/disable_streams()

Moi,

On Fri, Apr 05, 2024 at 12:14:25PM +0300, Tomi Valkeinen wrote:
> We support camera privacy leds with the .s_stream, in call_s_stream, but
> we don't have that support when the subdevice implements
> .enable/disable_streams.
> 
> Add the support by enabling the led when the first stream for a
> subdevice is enabled, and disabling the led then the last stream is
> disabled.
> 
> Signed-off-by: Tomi Valkeinen <tomi.valkeinen@...asonboard.com>
> ---
>  drivers/media/v4l2-core/v4l2-subdev.c | 12 ++++++++++++
>  1 file changed, 12 insertions(+)
> 
> diff --git a/drivers/media/v4l2-core/v4l2-subdev.c b/drivers/media/v4l2-core/v4l2-subdev.c
> index b4981447961a..015f2fb423c9 100644
> --- a/drivers/media/v4l2-core/v4l2-subdev.c
> +++ b/drivers/media/v4l2-core/v4l2-subdev.c
> @@ -2149,6 +2149,7 @@ int v4l2_subdev_enable_streams(struct v4l2_subdev *sd, u32 pad,
>  {
>  	struct device *dev = sd->entity.graph_obj.mdev->dev;
>  	struct v4l2_subdev_state *state;
> +	bool already_streaming;
>  	u64 found_streams = 0;
>  	unsigned int i;
>  	int ret;
> @@ -2197,6 +2198,11 @@ int v4l2_subdev_enable_streams(struct v4l2_subdev *sd, u32 pad,
>  
>  	dev_dbg(dev, "enable streams %u:%#llx\n", pad, streams_mask);
>  
> +	already_streaming = v4l2_subdev_is_streaming(sd);
> +
> +	if (!already_streaming)
> +		v4l2_subdev_enable_privacy_led(sd);
> +
>  	/* Call the .enable_streams() operation. */
>  	ret = v4l2_subdev_call(sd, pad, enable_streams, state, pad,
>  			       streams_mask);
> @@ -2216,6 +2222,9 @@ int v4l2_subdev_enable_streams(struct v4l2_subdev *sd, u32 pad,
>  	}
>  
>  done:
> +	if (ret && !already_streaming)
> +		v4l2_subdev_disable_privacy_led(sd);

I think you could also lit the LED only if enabling streaming succeeds.

> +
>  	v4l2_subdev_unlock_state(state);
>  
>  	return ret;
> @@ -2339,6 +2348,9 @@ int v4l2_subdev_disable_streams(struct v4l2_subdev *sd, u32 pad,
>  	}
>  
>  done:
> +	if (!v4l2_subdev_is_streaming(sd))
> +		v4l2_subdev_disable_privacy_led(sd);
> +
>  	v4l2_subdev_unlock_state(state);
>  
>  	return ret;
> 

-- 
Terveisin,

Sakari Ailus