Re: [Intel-gfx] [PATCH 1/4] drm: add writeback pointers to drm_connector

[Jani Nikula <jani.nikula@linux.intel.com>]

On Fri, 17 Dec 2021, "Kandpal, Suraj" <suraj.kandpal@intel.com> wrote:
> From: suraj kandpal <suraj.kandpal@intel.com>
>
> Adding drm_writeback_connector to drm_connector so that
> writeback_connector can be fetched from drm_connector

This needs some explaining, since drm_connector_to_writeback() does
exactly that.

> Adding drm_connector and drm_encoder pointers in drm_writeback_connector

Why?

We can all read the code, the commit message should mostly be about the
*why*.

Also, drm changes should Cc: dri-devel mailing list.


BR,
Jani.

>
> Signed-off-by: suraj kandpal <suraj.kandpal@intel.com>
> ---
>  drivers/gpu/drm/drm_writeback.c | 19 ++++++++++---------
>  include/drm/drm_connector.h     |  3 +++
>  include/drm/drm_writeback.h     |  6 +++---
>  3 files changed, 16 insertions(+), 12 deletions(-)
>
> diff --git a/drivers/gpu/drm/drm_writeback.c b/drivers/gpu/drm/drm_writeback.c
> index dccf4504f1bb..47238db42363 100644
> --- a/drivers/gpu/drm/drm_writeback.c
> +++ b/drivers/gpu/drm/drm_writeback.c
> @@ -87,7 +87,7 @@ static const char *drm_writeback_fence_get_driver_name(struct dma_fence *fence)
>  	struct drm_writeback_connector *wb_connector =
>  		fence_to_wb_connector(fence);
>  
> -	return wb_connector->base.dev->driver->name;
> +	return wb_connector->base->dev->driver->name;
>  }
>  
>  static const char *
> @@ -177,7 +177,7 @@ int drm_writeback_connector_init(struct drm_device *dev,
>  				 const u32 *formats, int n_formats)
>  {
>  	struct drm_property_blob *blob;
> -	struct drm_connector *connector = &wb_connector->base;
> +	struct drm_connector *connector = wb_connector->base;
>  	struct drm_mode_config *config = &dev->mode_config;
>  	int ret = create_writeback_properties(dev);
>  
> @@ -189,14 +189,15 @@ int drm_writeback_connector_init(struct drm_device *dev,
>  	if (IS_ERR(blob))
>  		return PTR_ERR(blob);
>  
> -	drm_encoder_helper_add(&wb_connector->encoder, enc_helper_funcs);
> -	ret = drm_encoder_init(dev, &wb_connector->encoder,
> +	drm_encoder_helper_add(wb_connector->encoder, enc_helper_funcs);
> +	ret = drm_encoder_init(dev, wb_connector->encoder,
>  			       &drm_writeback_encoder_funcs,
>  			       DRM_MODE_ENCODER_VIRTUAL, NULL);
>  	if (ret)
>  		goto fail;
>  
>  	connector->interlace_allowed = 0;
> +	connector->wb_connector = wb_connector;
>  
>  	ret = drm_connector_init(dev, connector, con_funcs,
>  				 DRM_MODE_CONNECTOR_WRITEBACK);
> @@ -204,7 +205,7 @@ int drm_writeback_connector_init(struct drm_device *dev,
>  		goto connector_fail;
>  
>  	ret = drm_connector_attach_encoder(connector,
> -						&wb_connector->encoder);
> +						wb_connector->encoder);
>  	if (ret)
>  		goto attach_fail;
>  
> @@ -233,7 +234,7 @@ int drm_writeback_connector_init(struct drm_device *dev,
>  attach_fail:
>  	drm_connector_cleanup(connector);
>  connector_fail:
> -	drm_encoder_cleanup(&wb_connector->encoder);
> +	drm_encoder_cleanup(wb_connector->encoder);
>  fail:
>  	drm_property_blob_put(blob);
>  	return ret;
> @@ -263,7 +264,7 @@ int drm_writeback_prepare_job(struct drm_writeback_job *job)
>  {
>  	struct drm_writeback_connector *connector = job->connector;
>  	const struct drm_connector_helper_funcs *funcs =
> -		connector->base.helper_private;
> +		connector->base->helper_private;
>  	int ret;
>  
>  	if (funcs->prepare_writeback_job) {
> @@ -315,7 +316,7 @@ void drm_writeback_cleanup_job(struct drm_writeback_job *job)
>  {
>  	struct drm_writeback_connector *connector = job->connector;
>  	const struct drm_connector_helper_funcs *funcs =
> -		connector->base.helper_private;
> +		connector->base->helper_private;
>  
>  	if (job->prepared && funcs->cleanup_writeback_job)
>  		funcs->cleanup_writeback_job(connector, job);
> @@ -401,7 +402,7 @@ drm_writeback_get_out_fence(struct drm_writeback_connector *wb_connector)
>  {
>  	struct dma_fence *fence;
>  
> -	if (WARN_ON(wb_connector->base.connector_type !=
> +	if (WARN_ON(wb_connector->base->connector_type !=
>  		    DRM_MODE_CONNECTOR_WRITEBACK))
>  		return NULL;
>  
> diff --git a/include/drm/drm_connector.h b/include/drm/drm_connector.h
> index 379746d3266f..ec049b1bc4bb 100644
> --- a/include/drm/drm_connector.h
> +++ b/include/drm/drm_connector.h
> @@ -42,6 +42,7 @@ struct drm_property_blob;
>  struct drm_printer;
>  struct edid;
>  struct i2c_adapter;
> +struct drm_writeback_connector;
>  
>  enum drm_connector_force {
>  	DRM_FORCE_UNSPECIFIED,
> @@ -1483,6 +1484,8 @@ struct drm_connector {
>  	 */
>  	struct drm_encoder *encoder;
>  
> +	struct drm_writeback_connector *wb_connector;
> +
>  #define MAX_ELD_BYTES	128
>  	/** @eld: EDID-like data, if present */
>  	uint8_t eld[MAX_ELD_BYTES];
> diff --git a/include/drm/drm_writeback.h b/include/drm/drm_writeback.h
> index 9697d2714d2a..078c9907219c 100644
> --- a/include/drm/drm_writeback.h
> +++ b/include/drm/drm_writeback.h
> @@ -22,7 +22,7 @@ struct drm_writeback_connector {
>  	/**
>  	 * @base: base drm_connector object
>  	 */
> -	struct drm_connector base;
> +	struct drm_connector *base;
>  
>  	/**
>  	 * @encoder: Internal encoder used by the connector to fulfill
> @@ -31,7 +31,7 @@ struct drm_writeback_connector {
>  	 * by passing the @enc_funcs parameter to drm_writeback_connector_init()
>  	 * function.
>  	 */
> -	struct drm_encoder encoder;
> +	struct drm_encoder *encoder;
>  
>  	/**
>  	 * @pixel_formats_blob_ptr:
> @@ -143,7 +143,7 @@ struct drm_writeback_job {
>  static inline struct drm_writeback_connector *
>  drm_connector_to_writeback(struct drm_connector *connector)
>  {
> -	return container_of(connector, struct drm_writeback_connector, base);
> +	return connector->wb_connector;
>  }
>  
>  int drm_writeback_connector_init(struct drm_device *dev,

-- 
Jani Nikula, Intel Open Source Graphics Center