[PATCH] drm/amdgpu: check ring being ready before using

[Ding, Pixel]

Christian,

Thank you for the quick comments. The revision is coming soon.

— 
Sincerely Yours,
Pixel








On 18/01/2017, 9:26 PM, "Christian König" <deathsimple at vodafone.de> wrote:

>Am 18.01.2017 um 11:37 schrieb Pixel Ding:
>> From: Ding Pixel <pding at amd.com>
>>
>> Return success when the ring is properly initialized, otherwise return
>> failure.
>>
>> Tonga SRIOV VF doesn't have UVD and VCE engines, the initialization of
>> these IPs is bypassed. The system crashes if application submit IB to
>> their rings which are not ready to use. It could be a common issue if
>> IP having ring buffer is disabled for some reason on specific ASIC, so
>> it should check the ring being ready to use.
>>
>> Bug: amdgpu_test crashes system on Tonga VF.
>
>Good catch, we probably have problem using the second VCE ring as well.
>
>>
>> Signed-off-by: Ding Pixel <pding at amd.com>
>> ---
>>   drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c | 6 ++++++
>>   1 file changed, 6 insertions(+)
>>
>> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c
>> index 08dd97b..0a235b9 100644
>> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c
>> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c
>> @@ -83,6 +83,12 @@ int amdgpu_cs_get_ring(struct amdgpu_device *adev, u32 ip_type,
>>   		}
>>   		break;
>>   	}
>> +
>> +	if (!(*out_ring && (*out_ring)->ready)) {
>
>Don't check ring->ready here, that member is used during GPU reset to 
>test if we have successfully restarted the ring.
>
>Instead check if ring->adev is set, that is used in ring_init() to check 
>if a ring is initialized or not.
>
>> +		DRM_ERROR("invalid ip type: %d\n", ip_type);
>
>Please adjust the error message to something like "ring %d not 
>initialized on IP %d\".
>
>Regards,
>Christian.
>
>> +		return -EINVAL;
>> +	}
>> +
>>   	return 0;
>>   }
>>   
>
>