linux-kernel - Re: [PATCH v3 6/9] media: subdev: Add v4l2_subdev_is

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Message-ID: <20240412181558.GI31122@pendragon.ideasonboard.com>
Date: Fri, 12 Apr 2024 21:15:58 +0300
From: Laurent Pinchart <laurent.pinchart@...asonboard.com>
To: Tomi Valkeinen <tomi.valkeinen@...asonboard.com>
Cc: Mauro Carvalho Chehab <mchehab@...nel.org>,
	Hans Verkuil <hverkuil@...all.nl>,
	Sakari Ailus <sakari.ailus@...ux.intel.com>,
	Umang Jain <umang.jain@...asonboard.com>,
	linux-media@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH v3 6/9] media: subdev: Add v4l2_subdev_is_streaming()

Hi Tomi,

Thank you for the patch.

On Wed, Apr 10, 2024 at 03:35:53PM +0300, Tomi Valkeinen wrote:
> Add a helper function which returns whether the subdevice is streaming,
> i.e. if .s_stream or .enable_streams has been called successfully.
> 
> Signed-off-by: Tomi Valkeinen <tomi.valkeinen@...asonboard.com>
> ---
>  drivers/media/v4l2-core/v4l2-subdev.c | 25 +++++++++++++++++++++++++
>  include/media/v4l2-subdev.h           | 13 +++++++++++++
>  2 files changed, 38 insertions(+)
> 
> diff --git a/drivers/media/v4l2-core/v4l2-subdev.c b/drivers/media/v4l2-core/v4l2-subdev.c
> index 3d2c9c224b8f..20b5a00cbeeb 100644
> --- a/drivers/media/v4l2-core/v4l2-subdev.c
> +++ b/drivers/media/v4l2-core/v4l2-subdev.c
> @@ -2419,6 +2419,31 @@ void v4l2_subdev_notify_event(struct v4l2_subdev *sd,
>  }
>  EXPORT_SYMBOL_GPL(v4l2_subdev_notify_event);
>  
> +bool v4l2_subdev_is_streaming(struct v4l2_subdev *sd)
> +{
> +	struct v4l2_subdev_state *state;
> +
> +	if (!v4l2_subdev_has_op(sd, pad, enable_streams))
> +		return sd->streaming_enabled;
> +
> +	state = v4l2_subdev_get_locked_active_state(sd);
> +
> +	if (!(sd->flags & V4L2_SUBDEV_FL_STREAMS))
> +		return !!sd->enabled_pads;

I think this can be moved above the
v4l2_subdev_get_locked_active_state() call.

Reviewed-by: Laurent Pinchart <laurent.pinchart@...asonboard.com>

Any plan to convert drivers to this ?

> +
> +	for (unsigned int i = 0; i < state->stream_configs.num_configs; ++i) {
> +		const struct v4l2_subdev_stream_config *cfg;
> +
> +		cfg = &state->stream_configs.configs[i];
> +
> +		if (cfg->enabled)
> +			return true;
> +	}
> +
> +	return false;
> +}
> +EXPORT_SYMBOL_GPL(v4l2_subdev_is_streaming);
> +
>  int v4l2_subdev_get_privacy_led(struct v4l2_subdev *sd)
>  {
>  #if IS_REACHABLE(CONFIG_LEDS_CLASS)
> diff --git a/include/media/v4l2-subdev.h b/include/media/v4l2-subdev.h
> index d6867511e9cf..270a4dfa5663 100644
> --- a/include/media/v4l2-subdev.h
> +++ b/include/media/v4l2-subdev.h
> @@ -1914,4 +1914,17 @@ extern const struct v4l2_subdev_ops v4l2_subdev_call_wrappers;
>  void v4l2_subdev_notify_event(struct v4l2_subdev *sd,
>  			      const struct v4l2_event *ev);
>  
> +/**
> + * v4l2_subdev_is_streaming() - Returns if the subdevice is streaming
> + * @sd: The subdevice
> + *
> + * v4l2_subdev_is_streaming() tells if the subdevice is currently streaming.
> + * "Streaming" here means whether .s_stream() or .enable_streams() has been
> + * successfully called, and the streaming has not yet been disabled.
> + *
> + * If the subdevice implements .enable_streams() this function must be called
> + * while holding the active state lock.
> + */
> +bool v4l2_subdev_is_streaming(struct v4l2_subdev *sd);
> +
>  #endif /* _V4L2_SUBDEV_H */
> 

-- 
Regards,

Laurent Pinchart