Re: [PATCH] drm/amdgpu: add ring buffer information in devcoredump

["Khatri, Sunil" <sukhatri@amd.com>]

On 3/11/2024 7:29 PM, Christian König wrote:
>
>
> Am 11.03.24 um 13:22 schrieb Sunil Khatri:
>> Add relevant ringbuffer information such as
>> rptr, wptr, ring name, ring size and also
>> the ring contents for each ring on a gpu reset.
>>
>> Signed-off-by: Sunil Khatri <sunil.khatri@amd.com>
>> ---
>>   drivers/gpu/drm/amd/amdgpu/amdgpu_reset.c | 21 +++++++++++++++++++++
>>   1 file changed, 21 insertions(+)
>>
>> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_reset.c 
>> b/drivers/gpu/drm/amd/amdgpu/amdgpu_reset.c
>> index 6d059f853adc..1992760039da 100644
>> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_reset.c
>> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_reset.c
>> @@ -215,6 +215,27 @@ amdgpu_devcoredump_read(char *buffer, loff_t 
>> offset, size_t count,
>>                  fault_info->status);
>>       }
>>   +    drm_printf(&p, "Ring buffer information\n");
>> +    for (int i = 0; i < coredump->adev->num_rings; i++) {
>> +        int j = 0;
>> +        struct amdgpu_ring *ring = coredump->adev->rings[i];
>> +
>> +        drm_printf(&p, "ring name: %s\n", ring->name);
>> +        drm_printf(&p, "Rptr: 0x%llx Wptr: 0x%llx\n",
>> +               amdgpu_ring_get_rptr(ring) & ring->buf_mask,
>> +               amdgpu_ring_get_wptr(ring) & ring->buf_mask);
>
> Don't apply the mask here. We do have some use cases where the rptr 
> and wptr are outside the ring buffer.
Sure i will remove the mask.
>
>> +        drm_printf(&p, "Ring size in dwords: %d\n",
>> +               ring->ring_size / 4);
>
> Rather print the mask as additional value here.
Does that help adding the mask value ?
>
>> +        drm_printf(&p, "Ring contents\n");
>> +        drm_printf(&p, "Offset \t Value\n");
>> +
>> +        while (j < ring->ring_size) {
>> +            drm_printf(&p, "0x%x \t 0x%x\n", j, ring->ring[j/4]);
>> +            j += 4;
>> +        }
>
>> +        drm_printf(&p, "Ring dumped\n");
>
> That seems superfluous.

Noted


Regards
Sunil

>
> Regards,
> Christian.
>
>> +    }
>> +
>>       if (coredump->reset_vram_lost)
>>           drm_printf(&p, "VRAM is lost due to GPU reset!\n");
>>       if (coredump->adev->reset_info.num_regs) {
>