Re: [PATCH RFC 11/15] drm: writeback: Add drm_writeback_connector cleanup

[Louis Chauvet]

Le 27/08/24 - 16:33, Maxime Ripard a écrit :
> Hi,
> 
> On Wed, Aug 14, 2024 at 04:36:33PM GMT, Louis Chauvet wrote:
> > Currently drm_writeback_connector are created by
> > drm_writeback_connector_init or drm_writeback_connector_init_with_encoder.
> > Both of the function uses drm_connector_init and drm_encoder_init, but
> > there is no way to properly clean those structure from outside.
> > 
> > This patch introduce the new function drm_writeback_connector_cleanup to
> > allow a proper cleanup.
> > 
> > Signed-off-by: Louis Chauvet <louis.chauvet@xxxxxxxxxxx>
> > ---
> >  drivers/gpu/drm/drm_writeback.c | 10 ++++++++++
> >  include/drm/drm_writeback.h     | 11 +++++++++++
> >  2 files changed, 21 insertions(+)
> > 
> > diff --git a/drivers/gpu/drm/drm_writeback.c b/drivers/gpu/drm/drm_writeback.c
> > index a031c335bdb9..505a4eb40f93 100644
> > --- a/drivers/gpu/drm/drm_writeback.c
> > +++ b/drivers/gpu/drm/drm_writeback.c
> > @@ -184,6 +184,7 @@ int drm_writeback_connector_init(struct drm_device *dev,
> >  	drm_encoder_helper_add(&wb_connector->encoder, enc_helper_funcs);
> >  
> >  	wb_connector->encoder.possible_crtcs = possible_crtcs;
> > +	wb_connector->managed_encoder = true;
> >  
> >  	ret = drm_encoder_init(dev, &wb_connector->encoder,
> >  			       &drm_writeback_encoder_funcs,
> > @@ -290,6 +291,15 @@ int drm_writeback_connector_init_with_encoder(struct drm_device *dev,
> >  }
> >  EXPORT_SYMBOL(drm_writeback_connector_init_with_encoder);
> >  
> > +void drm_writeback_connector_cleanup(struct drm_writeback_connector *wb_connector)
> > +{
> > +	drm_connector_cleanup(&wb_connector->base);
> > +	drm_property_blob_put(wb_connector->pixel_formats_blob_ptr);
> > +	if (wb_connector->managed_encoder)
> > +		drm_encoder_cleanup(&wb_connector->encoder);
> > +}
> > +EXPORT_SYMBOL(drm_writeback_connector_cleanup);
> > +
> >  int drm_writeback_set_fb(struct drm_connector_state *conn_state,
> >  			 struct drm_framebuffer *fb)
> >  {
> > diff --git a/include/drm/drm_writeback.h b/include/drm/drm_writeback.h
> > index 17e576c80169..e651c0c0c84c 100644
> > --- a/include/drm/drm_writeback.h
> > +++ b/include/drm/drm_writeback.h
> > @@ -35,6 +35,15 @@ struct drm_writeback_connector {
> >  	 */
> >  	struct drm_encoder encoder;
> >  
> > +	/**
> > +	 * @managed_encoder: Sets to true if @encoder was created by drm_writeback_connector_init()
> > +	 *
> > +	 * If the user used drm_writeback_connector_init_with_encoder() to create the connector,
> > +	 * @encoder is not valid and not managed by drm_writeback_connector. This fields allows
> > +	 * the drm_writeback_cleanup() function to properly destroy the encoder if needed.
> > +	 */
> > +	bool managed_encoder;
> > +
> 
> I think we should rather create drmm_writeback_connector variants,
> and make both deprecated in favor of these new functions.

Hi,

I can try to do it. If I understand correctly, you want to create two 
functions like this? 

	int drmm_writeback_connector_init([...]) {
		/* drmm and alloc as we want to let drm core to manage this 
		   encoder, no need to store it in drm_writeback_connector 
		   */
		enc = drmm_plain_encoder_alloc(...);

		return drmm_writeback_connector_init_with_encoder([...], enc);
	}

	int drmm_writeback_connector_init_with_encoder([...], enc) {
		con = drmm_connector_init([...]);

		drm_connector_attach_encoder(enc, con);

		/* Needed for pixel_formats_blob_ptr, base is already 
		   managed by drmm_connector_init. Maybe cleaning 
		   job_queue is also needed? */
		drmm_add_action_or_reset([...], &drm_writeback_connector_cleanup)
	}

Louis Chauvet
 
> Maxime