| Message ID | 20250325201021.1315080-1-vivek.kasireddy@intel.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | drm/virtio: Fix flickering issue seen with imported dmabufs | expand |
On 3/25/25 23:10, Vivek Kasireddy wrote: > We need to save the reservation object pointer associated with the > imported dmabuf in the newly created GEM object to allow > drm_gem_plane_helper_prepare_fb() to extract the exclusive fence > from it and attach it to the plane state during prepare phase. > This is needed to ensure that drm_atomic_helper_wait_for_fences() > correctly waits for the relevant fences (move, etc) associated with > the reservation object, thereby implementing proper synchronization. > > Otherwise, artifacts or slight flickering can be seen when apps > are dragged across the screen when running Gnome (Wayland). This > problem is mostly seen with dGPUs in the case where the FBs are > allocated in VRAM but need to be migrated to System RAM as they > are shared with virtio-gpu. > > Fixes: ca77f27a2665 ("drm/virtio: Import prime buffers from other devices as guest blobs") > Cc: Gerd Hoffmann <kraxel@redhat.com> > Cc: Dmitry Osipenko <dmitry.osipenko@collabora.com> > Cc: Gurchetan Singh <gurchetansingh@chromium.org> > Cc: Chia-I Wu <olvaffe@gmail.com> > Signed-off-by: Vivek Kasireddy <vivek.kasireddy@intel.com> > --- > drivers/gpu/drm/virtio/virtgpu_prime.c | 1 + > 1 file changed, 1 insertion(+) > > diff --git a/drivers/gpu/drm/virtio/virtgpu_prime.c b/drivers/gpu/drm/virtio/virtgpu_prime.c > index fe6a0b018571..ceb0401a000b 100644 > --- a/drivers/gpu/drm/virtio/virtgpu_prime.c > +++ b/drivers/gpu/drm/virtio/virtgpu_prime.c > @@ -332,6 +332,7 @@ struct drm_gem_object *virtgpu_gem_prime_import(struct drm_device *dev, > } > > obj->import_attach = attach; > + obj->resv = buf->resv; > get_dma_buf(buf); > > ret = virtgpu_dma_buf_init_obj(dev, bo, attach); Will be better to set obj->resv before drm_gem_private_object_init() since it checks whether obj->resv was pre-inited. I'll change it while applying, thanks. Reviewed-by: Dmitry Osipenko <dmitry.osipenko@collabora.com>
> Subject: Re: [PATCH] drm/virtio: Fix flickering issue seen with imported > dmabufs > > On 3/25/25 23:10, Vivek Kasireddy wrote: > > We need to save the reservation object pointer associated with the > > imported dmabuf in the newly created GEM object to allow > > drm_gem_plane_helper_prepare_fb() to extract the exclusive fence > > from it and attach it to the plane state during prepare phase. > > This is needed to ensure that drm_atomic_helper_wait_for_fences() > > correctly waits for the relevant fences (move, etc) associated with > > the reservation object, thereby implementing proper synchronization. > > > > Otherwise, artifacts or slight flickering can be seen when apps > > are dragged across the screen when running Gnome (Wayland). This > > problem is mostly seen with dGPUs in the case where the FBs are > > allocated in VRAM but need to be migrated to System RAM as they > > are shared with virtio-gpu. > > > > Fixes: ca77f27a2665 ("drm/virtio: Import prime buffers from other devices as > guest blobs") > > Cc: Gerd Hoffmann <kraxel@redhat.com> > > Cc: Dmitry Osipenko <dmitry.osipenko@collabora.com> > > Cc: Gurchetan Singh <gurchetansingh@chromium.org> > > Cc: Chia-I Wu <olvaffe@gmail.com> > > Signed-off-by: Vivek Kasireddy <vivek.kasireddy@intel.com> > > --- > > drivers/gpu/drm/virtio/virtgpu_prime.c | 1 + > > 1 file changed, 1 insertion(+) > > > > diff --git a/drivers/gpu/drm/virtio/virtgpu_prime.c > b/drivers/gpu/drm/virtio/virtgpu_prime.c > > index fe6a0b018571..ceb0401a000b 100644 > > --- a/drivers/gpu/drm/virtio/virtgpu_prime.c > > +++ b/drivers/gpu/drm/virtio/virtgpu_prime.c > > @@ -332,6 +332,7 @@ struct drm_gem_object > *virtgpu_gem_prime_import(struct drm_device *dev, > > } > > > > obj->import_attach = attach; > > + obj->resv = buf->resv; > > get_dma_buf(buf); > > > > ret = virtgpu_dma_buf_init_obj(dev, bo, attach); > > Will be better to set obj->resv before drm_gem_private_object_init() > since it checks whether obj->resv was pre-inited. I'll change it while > applying, thanks. Sounds good. Thank you Dmitry! Thanks, Vivek > > Reviewed-by: Dmitry Osipenko <dmitry.osipenko@collabora.com> > > -- > Best regards, > Dmitry
On 3/26/25 08:13, Kasireddy, Vivek wrote: >> Subject: Re: [PATCH] drm/virtio: Fix flickering issue seen with imported >> dmabufs >> >> On 3/25/25 23:10, Vivek Kasireddy wrote: >>> We need to save the reservation object pointer associated with the >>> imported dmabuf in the newly created GEM object to allow >>> drm_gem_plane_helper_prepare_fb() to extract the exclusive fence >>> from it and attach it to the plane state during prepare phase. >>> This is needed to ensure that drm_atomic_helper_wait_for_fences() >>> correctly waits for the relevant fences (move, etc) associated with >>> the reservation object, thereby implementing proper synchronization. >>> >>> Otherwise, artifacts or slight flickering can be seen when apps >>> are dragged across the screen when running Gnome (Wayland). This >>> problem is mostly seen with dGPUs in the case where the FBs are >>> allocated in VRAM but need to be migrated to System RAM as they >>> are shared with virtio-gpu. >>> >>> Fixes: ca77f27a2665 ("drm/virtio: Import prime buffers from other devices as >> guest blobs") >>> Cc: Gerd Hoffmann <kraxel@redhat.com> >>> Cc: Dmitry Osipenko <dmitry.osipenko@collabora.com> >>> Cc: Gurchetan Singh <gurchetansingh@chromium.org> >>> Cc: Chia-I Wu <olvaffe@gmail.com> >>> Signed-off-by: Vivek Kasireddy <vivek.kasireddy@intel.com> >>> --- >>> drivers/gpu/drm/virtio/virtgpu_prime.c | 1 + >>> 1 file changed, 1 insertion(+) >>> >>> diff --git a/drivers/gpu/drm/virtio/virtgpu_prime.c >> b/drivers/gpu/drm/virtio/virtgpu_prime.c >>> index fe6a0b018571..ceb0401a000b 100644 >>> --- a/drivers/gpu/drm/virtio/virtgpu_prime.c >>> +++ b/drivers/gpu/drm/virtio/virtgpu_prime.c >>> @@ -332,6 +332,7 @@ struct drm_gem_object >> *virtgpu_gem_prime_import(struct drm_device *dev, >>> } >>> >>> obj->import_attach = attach; >>> + obj->resv = buf->resv; >>> get_dma_buf(buf); >>> >>> ret = virtgpu_dma_buf_init_obj(dev, bo, attach); >> >> Will be better to set obj->resv before drm_gem_private_object_init() >> since it checks whether obj->resv was pre-inited. I'll change it while >> applying, thanks. > Sounds good. Thank you Dmitry! Applied to misc-fixes, thanks! Will keep an eye on the patch status in the misc. Too early to apply now to misc-fixes, I rushed a bit by accident.
diff --git a/drivers/gpu/drm/virtio/virtgpu_prime.c b/drivers/gpu/drm/virtio/virtgpu_prime.c index fe6a0b018571..ceb0401a000b 100644 --- a/drivers/gpu/drm/virtio/virtgpu_prime.c +++ b/drivers/gpu/drm/virtio/virtgpu_prime.c @@ -332,6 +332,7 @@ struct drm_gem_object *virtgpu_gem_prime_import(struct drm_device *dev, } obj->import_attach = attach; + obj->resv = buf->resv; get_dma_buf(buf); ret = virtgpu_dma_buf_init_obj(dev, bo, attach);
We need to save the reservation object pointer associated with the imported dmabuf in the newly created GEM object to allow drm_gem_plane_helper_prepare_fb() to extract the exclusive fence from it and attach it to the plane state during prepare phase. This is needed to ensure that drm_atomic_helper_wait_for_fences() correctly waits for the relevant fences (move, etc) associated with the reservation object, thereby implementing proper synchronization. Otherwise, artifacts or slight flickering can be seen when apps are dragged across the screen when running Gnome (Wayland). This problem is mostly seen with dGPUs in the case where the FBs are allocated in VRAM but need to be migrated to System RAM as they are shared with virtio-gpu. Fixes: ca77f27a2665 ("drm/virtio: Import prime buffers from other devices as guest blobs") Cc: Gerd Hoffmann <kraxel@redhat.com> Cc: Dmitry Osipenko <dmitry.osipenko@collabora.com> Cc: Gurchetan Singh <gurchetansingh@chromium.org> Cc: Chia-I Wu <olvaffe@gmail.com> Signed-off-by: Vivek Kasireddy <vivek.kasireddy@intel.com> --- drivers/gpu/drm/virtio/virtgpu_prime.c | 1 + 1 file changed, 1 insertion(+)