[PATCH] drm: Fix locking cargo-cult in encoder/plane init/cleanup

[Daniel Vetter]

On Tue, Nov 29, 2016 at 10:39:03AM +0000, Frank Binns wrote:
> On 29/11/16 09:45, Daniel Vetter wrote:
> > Encoders&planes can't be hotplugged, we dont need looking for this
> 
> s/looking/locking/
> 
> With that changed:
> Reviewed-by: Frank Binns <frank.binns at imgtec.com>

Fixed&applied, thanks for your review.
-Daniel

> 
> > since it's all single-threaded driver setup/teardown code. CRTCs
> > already don't grab locks.
> > 
> > While at it I noticed that plane's are missing the
> > drm_modeset_lock_fini() call, so add it.
> > 
> > Signed-off-by: Daniel Vetter <daniel.vetter at intel.com>
> > ---
> >   drivers/gpu/drm/drm_encoder.c | 9 +--------
> >   drivers/gpu/drm/drm_plane.c   | 4 ++--
> >   2 files changed, 3 insertions(+), 10 deletions(-)
> > 
> > diff --git a/drivers/gpu/drm/drm_encoder.c b/drivers/gpu/drm/drm_encoder.c
> > index 5c067719164d..992879f15f23 100644
> > --- a/drivers/gpu/drm/drm_encoder.c
> > +++ b/drivers/gpu/drm/drm_encoder.c
> > @@ -110,11 +110,9 @@ int drm_encoder_init(struct drm_device *dev,
> >   {
> >   	int ret;
> > -	drm_modeset_lock_all(dev);
> > -
> >   	ret = drm_mode_object_get(dev, &encoder->base, DRM_MODE_OBJECT_ENCODER);
> >   	if (ret)
> > -		goto out_unlock;
> > +		return ret;
> >   	encoder->dev = dev;
> >   	encoder->encoder_type = encoder_type;
> > @@ -142,9 +140,6 @@ int drm_encoder_init(struct drm_device *dev,
> >   	if (ret)
> >   		drm_mode_object_unregister(dev, &encoder->base);
> > -out_unlock:
> > -	drm_modeset_unlock_all(dev);
> > -
> >   	return ret;
> >   }
> >   EXPORT_SYMBOL(drm_encoder_init);
> > @@ -164,12 +159,10 @@ void drm_encoder_cleanup(struct drm_encoder *encoder)
> >   	 * the indices on the drm_encoder after us in the encoder_list.
> >   	 */
> > -	drm_modeset_lock_all(dev);
> >   	drm_mode_object_unregister(dev, &encoder->base);
> >   	kfree(encoder->name);
> >   	list_del(&encoder->head);
> >   	dev->mode_config.num_encoder--;
> > -	drm_modeset_unlock_all(dev);
> >   	memset(encoder, 0, sizeof(*encoder));
> >   }
> > diff --git a/drivers/gpu/drm/drm_plane.c b/drivers/gpu/drm/drm_plane.c
> > index 419ac313c36f..9147aab182c4 100644
> > --- a/drivers/gpu/drm/drm_plane.c
> > +++ b/drivers/gpu/drm/drm_plane.c
> > @@ -221,7 +221,8 @@ void drm_plane_cleanup(struct drm_plane *plane)
> >   {
> >   	struct drm_device *dev = plane->dev;
> > -	drm_modeset_lock_all(dev);
> > +	drm_modeset_lock_fini(&plane->mutex);
> > +
> >   	kfree(plane->format_types);
> >   	drm_mode_object_unregister(dev, &plane->base);
> > @@ -236,7 +237,6 @@ void drm_plane_cleanup(struct drm_plane *plane)
> >   	dev->mode_config.num_total_plane--;
> >   	if (plane->type == DRM_PLANE_TYPE_OVERLAY)
> >   		dev->mode_config.num_overlay_plane--;
> > -	drm_modeset_unlock_all(dev);
> >   	WARN_ON(plane->state && !plane->funcs->atomic_destroy_state);
> >   	if (plane->state && plane->funcs->atomic_destroy_state)
> 

-- 
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch