On Wed, 14 Feb 2024 at 20:02, Abhinav Kumar <quic_abhinavk@xxxxxxxxxxx> wrote: > > > > On 2/8/2024 6:50 AM, Dmitry Baryshkov wrote: > > We have several reports of vblank timeout messages. However after some > > debugging it was found that there might be different causes to that. > > To allow us to identify the DPU block that gets stuck, include the > > actual CTL_FLUSH value into the timeout message and trigger the devcore > > snapshot capture. > > > > Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@xxxxxxxxxx> > > --- > > Changes in v2: > > - Added a call to msm_disp_snapshot_state() to trigger devcore dump > > (Abhinav) > > - Link to v1: https://lore.kernel.org/r/20240106-fd-dpu-debug-timeout-v1-1-6d9762884641@xxxxxxxxxx > > --- > > drivers/gpu/drm/msm/disp/dpu1/dpu_encoder_phys_vid.c | 3 ++- > > 1 file changed, 2 insertions(+), 1 deletion(-) > > > > 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 d0f56c5c4cce..a8d6165b3c0a 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 > > @@ -489,7 +489,8 @@ static int dpu_encoder_phys_vid_wait_for_commit_done( > > (hw_ctl->ops.get_flush_register(hw_ctl) == 0), > > msecs_to_jiffies(50)); > > if (ret <= 0) { > > - DPU_ERROR("vblank timeout\n"); > > + DPU_ERROR("vblank timeout: %x\n", hw_ctl->ops.get_flush_register(hw_ctl)); > > + msm_disp_snapshot_state(phys_enc->parent->dev); > > > There is no rate limiting in this piece of code unfortunately. So this > will flood the number of snapshots. Well... Yes and no. The devcoredump will destroy other snapshots if there is a pending one. So only the console will be flooded and only in case when MSM_DISP_SNAPSHOT_DUMP_IN_CONSOLE is enabled. > > Short-term solution is you can go with a vblank_timeout_cnt and reset it > in the enable() like other similar error counters. > > long-term solution is we need to centralize these error locations to one > single dpu_encoder_error_handler() with a single counter and the error > handler will print out the error code along with the snapshot instead of > the snapshot being called from all over the place. > > > > > return -ETIMEDOUT; > > } > > > > > > --- > > base-commit: 39676dfe52331dba909c617f213fdb21015c8d10 > > change-id: 20240106-fd-dpu-debug-timeout-e917f0bc8063 > > > > Best regards, -- With best wishes Dmitry
