[PATCH] drm/msm/dpu: Capture dpu snapshot when frame_done_timer timeouts

[Paloma Arellano]

On 11/27/2023 5:48 PM, Dmitry Baryshkov wrote:
> On Tue, 28 Nov 2023 at 03:12, Paloma Arellano <quic_parellan at quicinc.com> wrote:
>> Trigger a devcoredump to dump dpu registers and capture the drm atomic
>> state when the frame_done_timer timeouts.
>>
>> Signed-off-by: Paloma Arellano <quic_parellan at quicinc.com>
>> ---
>>   drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c | 13 +++++++++++--
>>   1 file changed, 11 insertions(+), 2 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c
>> index 1cf7ff6caff4..5cf7594feb5a 100644
>> --- a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c
>> +++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c
>> @@ -191,6 +191,7 @@ struct dpu_encoder_virt {
>>          void *crtc_frame_event_cb_data;
>>
>>          atomic_t frame_done_timeout_ms;
>> +       atomic_t frame_done_timeout_cnt;
>>          struct timer_list frame_done_timer;
>>
>>          struct msm_display_info disp_info;
>> @@ -1204,6 +1205,8 @@ static void dpu_encoder_virt_atomic_enable(struct drm_encoder *drm_enc,
>>
>>          dpu_enc->dsc = dpu_encoder_get_dsc_config(drm_enc);
>>
>> +       atomic_set(&dpu_enc->frame_done_timeout_cnt, 0);
>> +
>>          if (disp_info->intf_type == INTF_DP)
>>                  dpu_enc->wide_bus_en = msm_dp_wide_bus_available(priv->dp[index]);
>>          else if (disp_info->intf_type == INTF_DSI)
>> @@ -2115,11 +2118,12 @@ static int _dpu_encoder_status_show(struct seq_file *s, void *data)
>>          for (i = 0; i < dpu_enc->num_phys_encs; i++) {
>>                  struct dpu_encoder_phys *phys = dpu_enc->phys_encs[i];
>>
>> -               seq_printf(s, "intf:%d  wb:%d  vsync:%8d     underrun:%8d    ",
>> +               seq_printf(s, "intf:%d  wb:%d  vsync:%8d     underrun:%8d    frame_done_cnt:%d",
>>                                  phys->hw_intf ? phys->hw_intf->idx - INTF_0 : -1,
>>                                  phys->hw_wb ? phys->hw_wb->idx - WB_0 : -1,
>>                                  atomic_read(&phys->vsync_cnt),
>> -                               atomic_read(&phys->underrun_cnt));
>> +                               atomic_read(&phys->underrun_cnt),
>> +                               atomic_read(&dpu_enc->frame_done_timeout_cnt));
>>
>>                  seq_printf(s, "mode: %s\n", dpu_encoder_helper_get_intf_type(phys->intf_mode));
>>          }
>> @@ -2341,6 +2345,10 @@ static void dpu_encoder_frame_done_timeout(struct timer_list *t)
>>
>>          DPU_ERROR_ENC(dpu_enc, "frame done timeout\n");
>>
>> +       atomic_inc(&dpu_enc->frame_done_timeout_cnt);
>> +       if (atomic_read(&dpu_enc->frame_done_timeout_cnt) == 1)
>> +               msm_disp_snapshot_state(drm_enc->dev);
> atomic_inc_and_test(), please

Hi Dmitry,

We only want to create a snapshot for the first instance in which the 
timer timeouts. atomic_int_and_test() increments the value and then 
returns whether it has a value of zero or not. FWIW I think I should 
change it to 'atomic_add_return(1, &dpu_enc->frame_done_timeout_cnt)' so 
that we can check only when this value equals one.

Thank you,

Paloma

>
>> +
>>          event = DPU_ENCODER_FRAME_EVENT_ERROR;
>>          trace_dpu_enc_frame_done_timeout(DRMID(drm_enc), event);
>>          dpu_enc->crtc_frame_event_cb(dpu_enc->crtc_frame_event_cb_data, event);
>> @@ -2392,6 +2400,7 @@ struct drm_encoder *dpu_encoder_init(struct drm_device *dev,
>>                  goto fail;
>>
>>          atomic_set(&dpu_enc->frame_done_timeout_ms, 0);
>> +       atomic_set(&dpu_enc->frame_done_timeout_cnt, 0);
>>          timer_setup(&dpu_enc->frame_done_timer,
>>                          dpu_encoder_frame_done_timeout, 0);
>>
>> --
>> 2.41.0
>>
>