| Message ID | 20231123221315.3579454-1-javierm@redhat.com (mailing list archive) |
|---|---|
| Headers | show |
| Series | drm: Allow the damage helpers to handle buffer damage | expand |
Javier Martinez Canillas <javierm@redhat.com> writes: > Hello, > > This series is to fix an issue that surfaced after damage clipping was > enabled for the virtio-gpu by commit 01f05940a9a7 ("drm/virtio: Enable > fb damage clips property for the primary plane"). > > After that change, flickering artifacts was reported to be present with > both weston and wlroots wayland compositors when running in a virtual > machine. The cause was identified by Sima Vetter, who pointed out that > virtio-gpu does per-buffer uploads and for this reason it needs to do > a buffer damage handling, instead of frame damage handling. > > Their suggestion was to extend the damage helpers to cover that case > and given that there's isn't a buffer damage accumulation algorithm > (e.g: buffer age), just do a full plane update if the framebuffer that > is attached to a plane changed since the last plane update (page-flip). > > It is a v4 that addresses issues pointed out by Sima Vetter in v3: > > https://lists.freedesktop.org/archives/dri-devel/2023-November/431409.html > > Patch #1 adds a ignore_damage_clips field to struct drm_plane_state to be > set by drivers that want the damage helpers to ignore the damage clips. > > Patch #2 fixes the virtio-gpu damage handling logic by asking the damage > helper to ignore the damage clips if the framebuffer attached to a plane > has changed since the last page-flip. > > Patch #3 does the same but for the vmwgfx driver that also needs to handle > buffer damage and should have the same issue (although I haven't tested it > due not having a VMWare setup). > > Patch #4 adds to the KMS damage tracking kernel-doc some paragraphs about > damage tracking types and references to links that explain frame damage vs > buffer damage. > > Finally patch #5 adds an item to the DRM todo, about the need to implement > some buffer damage accumulation algorithm instead of just doing full plane > updates in this case. > > Because commit 01f05940a9a7 landed in v6.4, the first 2 patches are marked > as Fixes and Cc stable. > > I've tested this on a VM with weston, was able to reproduce the issue > reported and the patches did fix the problem. > > Best regards, > Javier > > Changes in v4: > - Refer in ignore_damage_clips kernel-doc to "Damage Tracking Properties" > KMS documentation section (Sima Vetter). > - Add another paragraph to "Damage Tracking Properties" section to mention > the fields that drivers with per-buffer upload target should check to set > drm_plane_state.ignore_damage_clips (Sima Vetter). > - Reference the &drm_plane_state.ignore_damage_clips and the damage helpers > in the buffer damage TODO entry (Sima Vetter). > > Changes in v3: > - Fix typo in the kernel-doc (Simon Ser). > - Add a paragraph explaining what the problem in the kernel is and > make it clear that the refeference documents are related to how > user-space handles this case (Thomas Zimmermann). > > Changes in v2: > - Add a struct drm_plane_state .ignore_damage_clips to set in the plane's > .atomic_check, instead of having different helpers (Thomas Zimmermann). > - Set struct drm_plane_state .ignore_damage_clips in virtio-gpu plane's > .atomic_check instead of using a different helpers (Thomas Zimmermann). > - Set struct drm_plane_state .ignore_damage_clips in vmwgfx plane's > .atomic_check instead of using a different helpers (Thomas Zimmermann). > > Javier Martinez Canillas (5): > drm: Allow drivers to indicate the damage helpers to ignore damage > clips > drm/virtio: Disable damage clipping if FB changed since last page-flip > drm/vmwgfx: Disable damage clipping if FB changed since last page-flip > drm/plane: Extend damage tracking kernel-doc > drm/todo: Add entry about implementing buffer age for damage tracking > Pushed to drm-misc (drm-misc-next). Thanks!
Hello, This series is to fix an issue that surfaced after damage clipping was enabled for the virtio-gpu by commit 01f05940a9a7 ("drm/virtio: Enable fb damage clips property for the primary plane"). After that change, flickering artifacts was reported to be present with both weston and wlroots wayland compositors when running in a virtual machine. The cause was identified by Sima Vetter, who pointed out that virtio-gpu does per-buffer uploads and for this reason it needs to do a buffer damage handling, instead of frame damage handling. Their suggestion was to extend the damage helpers to cover that case and given that there's isn't a buffer damage accumulation algorithm (e.g: buffer age), just do a full plane update if the framebuffer that is attached to a plane changed since the last plane update (page-flip). It is a v4 that addresses issues pointed out by Sima Vetter in v3: https://lists.freedesktop.org/archives/dri-devel/2023-November/431409.html Patch #1 adds a ignore_damage_clips field to struct drm_plane_state to be set by drivers that want the damage helpers to ignore the damage clips. Patch #2 fixes the virtio-gpu damage handling logic by asking the damage helper to ignore the damage clips if the framebuffer attached to a plane has changed since the last page-flip. Patch #3 does the same but for the vmwgfx driver that also needs to handle buffer damage and should have the same issue (although I haven't tested it due not having a VMWare setup). Patch #4 adds to the KMS damage tracking kernel-doc some paragraphs about damage tracking types and references to links that explain frame damage vs buffer damage. Finally patch #5 adds an item to the DRM todo, about the need to implement some buffer damage accumulation algorithm instead of just doing full plane updates in this case. Because commit 01f05940a9a7 landed in v6.4, the first 2 patches are marked as Fixes and Cc stable. I've tested this on a VM with weston, was able to reproduce the issue reported and the patches did fix the problem. Best regards, Javier Changes in v4: - Refer in ignore_damage_clips kernel-doc to "Damage Tracking Properties" KMS documentation section (Sima Vetter). - Add another paragraph to "Damage Tracking Properties" section to mention the fields that drivers with per-buffer upload target should check to set drm_plane_state.ignore_damage_clips (Sima Vetter). - Reference the &drm_plane_state.ignore_damage_clips and the damage helpers in the buffer damage TODO entry (Sima Vetter). Changes in v3: - Fix typo in the kernel-doc (Simon Ser). - Add a paragraph explaining what the problem in the kernel is and make it clear that the refeference documents are related to how user-space handles this case (Thomas Zimmermann). Changes in v2: - Add a struct drm_plane_state .ignore_damage_clips to set in the plane's .atomic_check, instead of having different helpers (Thomas Zimmermann). - Set struct drm_plane_state .ignore_damage_clips in virtio-gpu plane's .atomic_check instead of using a different helpers (Thomas Zimmermann). - Set struct drm_plane_state .ignore_damage_clips in vmwgfx plane's .atomic_check instead of using a different helpers (Thomas Zimmermann). Javier Martinez Canillas (5): drm: Allow drivers to indicate the damage helpers to ignore damage clips drm/virtio: Disable damage clipping if FB changed since last page-flip drm/vmwgfx: Disable damage clipping if FB changed since last page-flip drm/plane: Extend damage tracking kernel-doc drm/todo: Add entry about implementing buffer age for damage tracking Documentation/gpu/drm-kms.rst | 2 ++ Documentation/gpu/todo.rst | 23 ++++++++++++++++++++ drivers/gpu/drm/drm_damage_helper.c | 3 ++- drivers/gpu/drm/drm_plane.c | 30 ++++++++++++++++++++++++++ drivers/gpu/drm/virtio/virtgpu_plane.c | 10 +++++++++ drivers/gpu/drm/vmwgfx/vmwgfx_kms.c | 11 ++++++++++ include/drm/drm_plane.h | 10 +++++++++ 7 files changed, 88 insertions(+), 1 deletion(-)