[PATCH] drm/msm/dpu: Don't always set merge_3d pending flush

From: Jessica Zhang
Date: Wed Oct 09 2024 - 23:41:49 EST


Don't set the merge_3d pending flush bits if the mode_3d is
BLEND_3D_NONE.

Always flushing merge_3d can cause timeout issues when there are
multiple commits with concurrent writeback enabled.

This is because the video phys enc waits for the hw_ctl flush register
to be completely cleared [1] in its wait_for_commit_done(), but the WB
encoder always sets the merge_3d pending flush during each commit
regardless of if the merge_3d is actually active.

This means that the hw_ctl flush register will never be 0 when there are
multiple CWB commits and the video phys enc will hit vblank timeout
errors after the first CWB commit.

[1] commit fe9df3f50c39 ("drm/msm/dpu: add real wait_for_commit_done()")

Fixes: 3e79527a33a8 ("drm/msm/dpu: enable merge_3d support on sm8150/sm8250")
Fixes: d7d0e73f7de3 ("drm/msm/dpu: introduce the dpu_encoder_phys_* for writeback")
Signed-off-by: Jessica Zhang <quic_jesszhan@xxxxxxxxxxx>
---
drivers/gpu/drm/msm/disp/dpu1/dpu_encoder_phys_vid.c | 5 ++++-
drivers/gpu/drm/msm/disp/dpu1/dpu_encoder_phys_wb.c | 5 ++++-
2 files changed, 8 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder_phys_vid.c b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder_phys_vid.c
index ba8878d21cf0e1945a393cca806cb64f03b16640..8864ace938e03483492e25734f834fbdd615d127 100644
--- a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder_phys_vid.c
+++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder_phys_vid.c
@@ -440,10 +440,12 @@ static void dpu_encoder_phys_vid_enable(struct dpu_encoder_phys *phys_enc)
struct dpu_hw_ctl *ctl;
const struct msm_format *fmt;
u32 fmt_fourcc;
+ u32 mode_3d;

ctl = phys_enc->hw_ctl;
fmt_fourcc = dpu_encoder_get_drm_fmt(phys_enc);
fmt = mdp_get_format(&phys_enc->dpu_kms->base, fmt_fourcc, 0);
+ mode_3d = dpu_encoder_helper_get_3d_blend_mode(phys_enc);

DPU_DEBUG_VIDENC(phys_enc, "\n");

@@ -466,7 +468,8 @@ static void dpu_encoder_phys_vid_enable(struct dpu_encoder_phys *phys_enc)
goto skip_flush;

ctl->ops.update_pending_flush_intf(ctl, phys_enc->hw_intf->idx);
- if (ctl->ops.update_pending_flush_merge_3d && phys_enc->hw_pp->merge_3d)
+ if (mode_3d && ctl->ops.update_pending_flush_merge_3d &&
+ phys_enc->hw_pp->merge_3d)
ctl->ops.update_pending_flush_merge_3d(ctl, phys_enc->hw_pp->merge_3d->idx);

if (ctl->ops.update_pending_flush_cdm && phys_enc->hw_cdm)
diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder_phys_wb.c b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder_phys_wb.c
index 882c717859cec6dfc4b646200e68a748a5294ac9..07035ab77b792e76c08eb3e18c12a4afddeac902 100644
--- a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder_phys_wb.c
+++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder_phys_wb.c
@@ -275,6 +275,7 @@ static void _dpu_encoder_phys_wb_update_flush(struct dpu_encoder_phys *phys_enc)
struct dpu_hw_pingpong *hw_pp;
struct dpu_hw_cdm *hw_cdm;
u32 pending_flush = 0;
+ u32 mode_3d;

if (!phys_enc)
return;
@@ -283,6 +284,7 @@ static void _dpu_encoder_phys_wb_update_flush(struct dpu_encoder_phys *phys_enc)
hw_pp = phys_enc->hw_pp;
hw_ctl = phys_enc->hw_ctl;
hw_cdm = phys_enc->hw_cdm;
+ mode_3d = dpu_encoder_helper_get_3d_blend_mode(phys_enc);

DPU_DEBUG("[wb:%d]\n", hw_wb->idx - WB_0);

@@ -294,7 +296,8 @@ static void _dpu_encoder_phys_wb_update_flush(struct dpu_encoder_phys *phys_enc)
if (hw_ctl->ops.update_pending_flush_wb)
hw_ctl->ops.update_pending_flush_wb(hw_ctl, hw_wb->idx);

- if (hw_ctl->ops.update_pending_flush_merge_3d && hw_pp && hw_pp->merge_3d)
+ if (mode_3d && hw_ctl->ops.update_pending_flush_merge_3d &&
+ hw_pp && hw_pp->merge_3d)
hw_ctl->ops.update_pending_flush_merge_3d(hw_ctl,
hw_pp->merge_3d->idx);


---
base-commit: a20a91fb1bfac5d05ec5bcf9afe0c9363f6c8c93
change-id: 20241009-mode3d-fix-4c3c114ffeb9

Best regards,
--
Jessica Zhang <quic_jesszhan@xxxxxxxxxxx>