The RCAR-DU utilises a running VSPD pipeline to perform processing for the
display pipeline. This presents the opportunity for some race conditions to
affect the quality of the display output.
To prevent reporting page flips early, we must track this timing through the
VSP1, and only allow the rcar-du object to report the page-flip completion
event after the VSP1 has processed.
This series ensures that tearing and flicker is prevented, without introducing
any (substantial) performance impact.
These patches have been tested by introducing artificial delays in the commit
code paths and verifying that no visual tearing or flickering occurs.
Extensive testing around the race window has been performed by dynamically
adapting the artificial delay between 15, and 17 seconds in 100uS increments
for periods of 5 seconds on each delay test. These tests have successfully run
for 3 hours.
Manual start/stop testing has also been performed.
Mauro: As this patchset covers two subsystems, and the DRM/DU side is dependant
upon the media/VSP side, If you are happy with these patches, Would it be
possible to get acks from you for integration through the DRM tree please?
Regards
Kieran
Kieran Bingham (3):
v4l: vsp1: Postpone frame end handling in event of display list race
v4l: vsp1: Extend VSP1 module API to allow DRM callbacks
drm: rcar-du: Register a completion callback with VSP1
Laurent Pinchart (1):
drm: rcar-du: Arm the page flip event after queuing the page flip
drivers/gpu/drm/rcar-du/rcar_du_crtc.c | 30 ++++++++++++++------------
drivers/gpu/drm/rcar-du/rcar_du_crtc.h | 1 +-
drivers/gpu/drm/rcar-du/rcar_du_vsp.c | 9 ++++++++-
drivers/media/platform/vsp1/vsp1_dl.c | 19 ++++++++++++++--
drivers/media/platform/vsp1/vsp1_dl.h | 2 +-
drivers/media/platform/vsp1/vsp1_drm.c | 17 +++++++++++++++-
drivers/media/platform/vsp1/vsp1_drm.h | 11 ++++++++++-
drivers/media/platform/vsp1/vsp1_pipe.c | 13 ++++++++++-
include/media/vsp1.h | 7 ++++++-
9 files changed, 92 insertions(+), 17 deletions(-)
base-commit: 4df0f635a142c7498d20de9356851fb989c7f653
drm: rcar-du: Register a completion callback with VSP1
Currently we process page flip events on every display interrupt,
however this does not take into consideration the processing time needed
by the VSP1 utilised in the pipeline.
Register a callback with the VSP driver to obtain completion events, and
track them so that we only perform page flips when the full display
pipeline has completed for the frame.
Signed-off-by: Kieran Bingham <kieran.bingham+renesas@ideasonboard.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
3 files changed
