From: Stephen Boyd swboyd@chromium.org
[ Upstream commit c28d76d360f9f7af1f910342bde27939873bc45e ]
The 'vsync_cnt' is used to count the number of frames for a crtc. Unfortunately, we increment the count after waking up userspace via dpu_crtc_vblank_callback() calling drm_crtc_handle_vblank(). drm_crtc_handle_vblank() wakes up userspace processes that have called drm_wait_vblank_ioctl(), and if that ioctl is expecting the count to increase it won't.
Increment the count before calling into the drm APIs so that we don't have to worry about ordering the increment with anything else in drm. This fixes a software video decode test that fails to see frame counts increase on Trogdor boards.
Cc: Mark Yacoub markyacoub@chromium.org Cc: Jessica Zhang quic_jesszhan@quicinc.com Fixes: 885455d6bf82 ("drm/msm: Change dpu_crtc_get_vblank_counter to use vsync count.") Signed-off-by: Stephen Boyd swboyd@chromium.org Reviewed-by: Abhinav Kumar quic_abhinavk@quicinc.com Reviewed-by: Dmitry Baryshkov dmitry.baryshkov@linaro.org Tested-by: Jessica Zhang quic_jesszhan@quicinc.com # Trogdor (sc7180) Patchwork: https://patchwork.freedesktop.org/patch/490531/ Link: https://lore.kernel.org/r/20220622023855.2970913-1-swboyd@chromium.org Signed-off-by: Abhinav Kumar quic_abhinavk@quicinc.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c index 3940b9c6323b..fffd2ef897a0 100644 --- a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c +++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c @@ -1187,12 +1187,13 @@ static void dpu_encoder_vblank_callback(struct drm_encoder *drm_enc, DPU_ATRACE_BEGIN("encoder_vblank_callback"); dpu_enc = to_dpu_encoder_virt(drm_enc);
+ atomic_inc(&phy_enc->vsync_cnt); + spin_lock_irqsave(&dpu_enc->enc_spinlock, lock_flags); if (dpu_enc->crtc) dpu_crtc_vblank_callback(dpu_enc->crtc); spin_unlock_irqrestore(&dpu_enc->enc_spinlock, lock_flags);
- atomic_inc(&phy_enc->vsync_cnt); DPU_ATRACE_END("encoder_vblank_callback"); }