Re: [PATCH v3 6/8] drm/msm/dpu: add support for MDP_TOP blackhole

[Konrad Dybcio <konrad.dybcio@linaro.org>]

On 10/11/2022 21:19, Dmitry Baryshkov wrote:
> On 04/11/2022 16:58, Konrad Dybcio wrote:
>>
>> On 04/11/2022 14:03, Dmitry Baryshkov wrote:
>>> On sm8450 a register block was removed from MDP TOP. Accessing it during
>>> snapshotting results in NoC errors / immediate reboot. Skip accessing
>>> these registers during snapshot.
>>
>> Must have been fun to debug..
>>
>>
>>>
>>> Tested-by: Vinod Koul <vkoul@kernel.org>
>>> Reviewed-by: Vinod Koul <vkoul@kernel.org>
>>> Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
>>> ---
>>>   drivers/gpu/drm/msm/disp/dpu1/dpu_hw_catalog.h |  1 +
>>>   drivers/gpu/drm/msm/disp/dpu1/dpu_kms.c        | 11 +++++++++--
>>>   2 files changed, 10 insertions(+), 2 deletions(-)
>>>
>>> diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_catalog.h 
>>> b/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_catalog.h
>>> index 38aa38ab1568..4730f8268f2a 100644
>>> --- a/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_catalog.h
>>> +++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_catalog.h
>>> @@ -92,6 +92,7 @@ enum {
>>>       DPU_MDP_UBWC_1_0,
>>>       DPU_MDP_UBWC_1_5,
>>>       DPU_MDP_AUDIO_SELECT,
>>> +    DPU_MDP_PERIPH_0_REMOVED,
>>>       DPU_MDP_MAX
>>>   };
>>> diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_kms.c 
>>> b/drivers/gpu/drm/msm/disp/dpu1/dpu_kms.c
>>> index f3660cd14f4f..95d8765c1c53 100644
>>> --- a/drivers/gpu/drm/msm/disp/dpu1/dpu_kms.c
>>> +++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_kms.c
>>> @@ -927,8 +927,15 @@ static void dpu_kms_mdp_snapshot(struct 
>>> msm_disp_state *disp_state, struct msm_k
>>>           msm_disp_snapshot_add_block(disp_state, cat->wb[i].len,
>>>                   dpu_kms->mmio + cat->wb[i].base, "wb_%d", i);
>>> -    msm_disp_snapshot_add_block(disp_state, cat->mdp[0].len,
>>> -            dpu_kms->mmio + cat->mdp[0].base, "top");
>>> +    if (dpu_kms->hw_mdp->caps->features & 
>>> BIT(DPU_MDP_PERIPH_0_REMOVED)) {
>>> +        msm_disp_snapshot_add_block(disp_state, 0x380,
>>> +                dpu_kms->mmio + cat->mdp[0].base, "top");
>>> +        msm_disp_snapshot_add_block(disp_state, cat->mdp[0].len - 
>>> 0x3a8,
>>> +                dpu_kms->mmio + cat->mdp[0].base + 0x3a8, "top_2");
>>
>> Are these values expected to stay the same on different new-gen SoCs? 
>> Maybe it would
>>
>> be worth making it dynamic.
> 
> I do not want to overcomplicate this. Let's make it dynamic once there 
> is need for that. For now I expect this will be static.
Let's roll with that.

Reviewed-by: Konrad Dybcio <konrad.dybcio@linaro.org>

Konrad
> 
>>
>>
>> Konrad
>>
>>> +    } else {
>>> +        msm_disp_snapshot_add_block(disp_state, cat->mdp[0].len,
>>> +                dpu_kms->mmio + cat->mdp[0].base, "top");
>>> +    }
>>>       pm_runtime_put_sync(&dpu_kms->pdev->dev);
>>>   }
>