Re: [PATCH v2 8/9] media: subdev: Refactor v4l2_subdev_enable/disable_streams()

[Sakari Ailus]

Moi,

Thank you for working on this.

On Fri, Apr 05, 2024 at 12:14:26PM +0300, Tomi Valkeinen wrote:
> Add two internal helper functions, v4l2_subdev_collect_streams() and
> v4l2_subdev_set_streams_enabled(), which allows us to refactor
> v4l2_subdev_enable/disable_streams() functions.
> 
> This (I think) makes the code a bit easier to read, and lets us more
> easily add new functionality in the helper functions in the following
> patch.
> 
> Signed-off-by: Tomi Valkeinen <tomi.valkeinen@xxxxxxxxxxxxxxxx>
> ---
>  drivers/media/v4l2-core/v4l2-subdev.c | 111 +++++++++++++++++++---------------
>  1 file changed, 62 insertions(+), 49 deletions(-)
> 
> diff --git a/drivers/media/v4l2-core/v4l2-subdev.c b/drivers/media/v4l2-core/v4l2-subdev.c
> index 015f2fb423c9..6c3c9069f1e2 100644
> --- a/drivers/media/v4l2-core/v4l2-subdev.c
> +++ b/drivers/media/v4l2-core/v4l2-subdev.c
> @@ -2099,6 +2099,44 @@ int v4l2_subdev_routing_validate(struct v4l2_subdev *sd,
>  }
>  EXPORT_SYMBOL_GPL(v4l2_subdev_routing_validate);
>  
> +static void v4l2_subdev_collect_streams(struct v4l2_subdev *sd,
> +					struct v4l2_subdev_state *state,
> +					u32 pad, u64 streams_mask,
> +					u64 *found_streams,
> +					u64 *enabled_streams)
> +{
> +	*found_streams = 0;
> +	*enabled_streams = 0;
> +
> +	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];

You can do the assignment in declaration.

Same for streams_enabled() below.

> +
> +		if (cfg->pad != pad || !(streams_mask & BIT_ULL(cfg->stream)))
> +			continue;
> +
> +		*found_streams |= BIT_ULL(cfg->stream);
> +		if (cfg->enabled)
> +			*enabled_streams |= BIT_ULL(cfg->stream);
> +	}
> +}
> +
> +static void v4l2_subdev_set_streams_enabled(struct v4l2_subdev *sd,
> +					    struct v4l2_subdev_state *state,
> +					    u32 pad, u64 streams_mask,
> +					    bool enabled)
> +{
> +	for (unsigned int i = 0; i < state->stream_configs.num_configs; ++i) {
> +		struct v4l2_subdev_stream_config *cfg;
> +
> +		cfg = &state->stream_configs.configs[i];
> +
> +		if (cfg->pad == pad && (streams_mask & BIT_ULL(cfg->stream)))
> +			cfg->enabled = enabled;
> +	}
> +}
> +
>  static int v4l2_subdev_enable_streams_fallback(struct v4l2_subdev *sd, u32 pad,
>  					       u64 streams_mask)
>  {
> @@ -2150,8 +2188,8 @@ 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;
> +	u64 enabled_streams;
> +	u64 found_streams;
>  	int ret;
>  
>  	/* A few basic sanity checks first. */
> @@ -2172,22 +2210,9 @@ int v4l2_subdev_enable_streams(struct v4l2_subdev *sd, u32 pad,
>  	 * Verify that the requested streams exist and that they are not
>  	 * already enabled.
>  	 */
> -	for (i = 0; i < state->stream_configs.num_configs; ++i) {
> -		struct v4l2_subdev_stream_config *cfg =
> -			&state->stream_configs.configs[i];
>  
> -		if (cfg->pad != pad || !(streams_mask & BIT_ULL(cfg->stream)))
> -			continue;
> -
> -		found_streams |= BIT_ULL(cfg->stream);
> -
> -		if (cfg->enabled) {
> -			dev_dbg(dev, "stream %u already enabled on %s:%u\n",
> -				cfg->stream, sd->entity.name, pad);
> -			ret = -EALREADY;
> -			goto done;
> -		}
> -	}
> +	v4l2_subdev_collect_streams(sd, state, pad, streams_mask,
> +				    &found_streams, &enabled_streams);
>  
>  	if (found_streams != streams_mask) {
>  		dev_dbg(dev, "streams 0x%llx not found on %s:%u\n",
> @@ -2196,6 +2221,13 @@ int v4l2_subdev_enable_streams(struct v4l2_subdev *sd, u32 pad,
>  		goto done;
>  	}
>  
> +	if (enabled_streams) {
> +		dev_dbg(dev, "streams 0x%llx already enabled on %s:%u\n",
> +			enabled_streams, sd->entity.name, pad);
> +		ret = -EINVAL;
> +		goto done;
> +	}
> +
>  	dev_dbg(dev, "enable streams %u:%#llx\n", pad, streams_mask);
>  
>  	already_streaming = v4l2_subdev_is_streaming(sd);
> @@ -2213,13 +2245,7 @@ int v4l2_subdev_enable_streams(struct v4l2_subdev *sd, u32 pad,
>  	}
>  
>  	/* Mark the streams as enabled. */
> -	for (i = 0; i < state->stream_configs.num_configs; ++i) {
> -		struct v4l2_subdev_stream_config *cfg =
> -			&state->stream_configs.configs[i];
> -
> -		if (cfg->pad == pad && (streams_mask & BIT_ULL(cfg->stream)))
> -			cfg->enabled = true;
> -	}
> +	v4l2_subdev_set_streams_enabled(sd, state, pad, streams_mask, true);
>  
>  done:
>  	if (ret && !already_streaming)
> @@ -2281,8 +2307,8 @@ int v4l2_subdev_disable_streams(struct v4l2_subdev *sd, u32 pad,
>  {
>  	struct device *dev = sd->entity.graph_obj.mdev->dev;
>  	struct v4l2_subdev_state *state;
> -	u64 found_streams = 0;
> -	unsigned int i;
> +	u64 enabled_streams;
> +	u64 found_streams;
>  	int ret;
>  
>  	/* A few basic sanity checks first. */
> @@ -2303,22 +2329,9 @@ int v4l2_subdev_disable_streams(struct v4l2_subdev *sd, u32 pad,
>  	 * Verify that the requested streams exist and that they are not
>  	 * already disabled.
>  	 */
> -	for (i = 0; i < state->stream_configs.num_configs; ++i) {
> -		struct v4l2_subdev_stream_config *cfg =
> -			&state->stream_configs.configs[i];
>  
> -		if (cfg->pad != pad || !(streams_mask & BIT_ULL(cfg->stream)))
> -			continue;
> -
> -		found_streams |= BIT_ULL(cfg->stream);
> -
> -		if (!cfg->enabled) {
> -			dev_dbg(dev, "stream %u already disabled on %s:%u\n",
> -				cfg->stream, sd->entity.name, pad);
> -			ret = -EALREADY;
> -			goto done;
> -		}
> -	}
> +	v4l2_subdev_collect_streams(sd, state, pad, streams_mask,
> +				    &found_streams, &enabled_streams);
>  
>  	if (found_streams != streams_mask) {
>  		dev_dbg(dev, "streams 0x%llx not found on %s:%u\n",
> @@ -2327,6 +2340,13 @@ int v4l2_subdev_disable_streams(struct v4l2_subdev *sd, u32 pad,
>  		goto done;
>  	}
>  
> +	if (enabled_streams != streams_mask) {
> +		dev_dbg(dev, "streams 0x%llx already disabled on %s:%u\n",
> +			streams_mask & ~enabled_streams, sd->entity.name, pad);
> +		ret = -EINVAL;
> +		goto done;
> +	}
> +
>  	dev_dbg(dev, "disable streams %u:%#llx\n", pad, streams_mask);
>  
>  	/* Call the .disable_streams() operation. */
> @@ -2338,14 +2358,7 @@ int v4l2_subdev_disable_streams(struct v4l2_subdev *sd, u32 pad,
>  		goto done;
>  	}
>  
> -	/* Mark the streams as disabled. */
> -	for (i = 0; i < state->stream_configs.num_configs; ++i) {
> -		struct v4l2_subdev_stream_config *cfg =
> -			&state->stream_configs.configs[i];
> -
> -		if (cfg->pad == pad && (streams_mask & BIT_ULL(cfg->stream)))
> -			cfg->enabled = false;
> -	}
> +	v4l2_subdev_set_streams_enabled(sd, state, pad, streams_mask, false);
>  
>  done:
>  	if (!v4l2_subdev_is_streaming(sd))
> 

-- 
Terveisin,

Sakari Ailus