From: Rob Clark <robdclark@xxxxxxxxxxxx> Someone on IRC once asked an innocent enough sounding question: Why with xf86-video-modesetting is es2gears limited at 120fps. So I broke out the perfetto tracing mesa MR and took a look. It turns out the problem was drm_atomic_helper_dirtyfb(), which would end up waiting for vblank.. es2gears would rapidly push two frames to Xorg, which would blit them to screen and in idle hook (I assume) call the DIRTYFB ioctl. Which in turn would do an atomic update to flush the dirty rects, which would stall until the next vblank. And then the whole process would repeat. But this is a bit silly, we only need dirtyfb for command mode DSI panels. So lets just skip it otherwise. Rob Clark (2): drm: Fix dirtyfb stalls drm/msm/dpu: Wire up needs_dirtyfb drivers/gpu/drm/drm_damage_helper.c | 8 ++++++++ drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c | 14 ++++++++++++++ include/drm/drm_modeset_helper_vtables.h | 14 ++++++++++++++ 3 files changed, 36 insertions(+) -- 2.30.2
