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author | Rob Clark <robdclark@chromium.org> | 2022-02-23 11:11:08 -0800 |
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committer | Rob Clark <robdclark@chromium.org> | 2022-02-25 07:59:58 -0800 |
commit | 9e4dde28e9cd34ee13a6b7247f0857fb49fd3f19 (patch) | |
tree | 17fee6c9091477bc662c43c372e91dfa203539f9 /drivers/gpu/drm/msm/disp/mdp5/mdp5_crtc.c | |
parent | db22583d6c7da2b20965514a123705cf753c931a (diff) | |
download | linux-9e4dde28e9cd34ee13a6b7247f0857fb49fd3f19.tar.bz2 |
drm/msm: Avoid dirtyfb stalls on video mode displays (v2)
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 track in plane state whether dirtyfb is required, and
track in the fb how many attached planes require dirtyfb so that we
can skip it when not required. (Note, mdp4 does not actually have
cmd mode support.)
Signed-off-by: Rob Clark <robdclark@chromium.org>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Link: https://lore.kernel.org/r/20220223191118.881321-1-robdclark@gmail.com
Signed-off-by: Rob Clark <robdclark@chromium.org>
Diffstat (limited to 'drivers/gpu/drm/msm/disp/mdp5/mdp5_crtc.c')
-rw-r--r-- | drivers/gpu/drm/msm/disp/mdp5/mdp5_crtc.c | 8 |
1 files changed, 8 insertions, 0 deletions
diff --git a/drivers/gpu/drm/msm/disp/mdp5/mdp5_crtc.c b/drivers/gpu/drm/msm/disp/mdp5/mdp5_crtc.c index bb7d066618e6..b966cd69f99d 100644 --- a/drivers/gpu/drm/msm/disp/mdp5/mdp5_crtc.c +++ b/drivers/gpu/drm/msm/disp/mdp5/mdp5_crtc.c @@ -690,6 +690,8 @@ static int mdp5_crtc_atomic_check(struct drm_crtc *crtc, { struct drm_crtc_state *crtc_state = drm_atomic_get_new_crtc_state(state, crtc); + struct mdp5_crtc_state *mdp5_cstate = to_mdp5_crtc_state(crtc_state); + struct mdp5_interface *intf = mdp5_cstate->pipeline.intf; struct mdp5_kms *mdp5_kms = get_kms(crtc); struct drm_plane *plane; struct drm_device *dev = crtc->dev; @@ -706,12 +708,18 @@ static int mdp5_crtc_atomic_check(struct drm_crtc *crtc, DBG("%s: check", crtc->name); drm_atomic_crtc_state_for_each_plane_state(plane, pstate, crtc_state) { + struct mdp5_plane_state *mdp5_pstate = + to_mdp5_plane_state(pstate); + if (!pstate->visible) continue; pstates[cnt].plane = plane; pstates[cnt].state = to_mdp5_plane_state(pstate); + mdp5_pstate->needs_dirtyfb = + intf->mode == MDP5_INTF_DSI_MODE_COMMAND; + /* * if any plane on this crtc uses 2 hwpipes, then we need * the crtc to have a right hwmixer. |