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 --- 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 3a462e327e0e..a1b8c4592943 100644 --- a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c +++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c @@ -1251,12 +1251,13 @@ 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"); }
base-commit: f2906aa863381afb0015a9eb7fefad885d4e5a56