[PATCH] drm/amdgpu: limit VCN instance number to 1 for NAVY_FLOUNDER

[Lazar, Lijo]

On 10/21/2021 6:10 PM, Chen, Guchun wrote:
> Hi Lijo,
> 
> Alex has a following fix "85db7fcb2e53 drm/amdgpu: get VCN harvest information from IP discovery table" to fix that logic.

But the logic applied in this fix tells that anything in IP discovery 
(version table or harvest table) doesn't solve the problem. This is 
equivalent to an ASIC specific logic similar to old ASIC enum checks.

> 
> For other ASCIs like DIMGREY_CAVEFISH and BEIGE_GOBY, its instance num is 1, match with VBIOS discovery table. So there is no need to handle it.
> 

Thanks for the clarification! It looks good to me, will leave it to 
Alex/Leo/James.

Thanks,
Lijo

> Regards,
> Guchun
> 
> -----Original Message-----
> From: Lazar, Lijo <Lijo.Lazar at amd.com>
> Sent: Thursday, October 21, 2021 5:45 PM
> To: Chen, Guchun <Guchun.Chen at amd.com>; amd-gfx at lists.freedesktop.org; Koenig, Christian <Christian.Koenig at amd.com>; Pan, Xinhui <Xinhui.Pan at amd.com>; Deucher, Alexander <Alexander.Deucher at amd.com>; Liu, Leo <Leo.Liu at amd.com>
> Subject: Re: [PATCH] drm/amdgpu: limit VCN instance number to 1 for NAVY_FLOUNDER
> 
> 
> 
> On 10/21/2021 12:45 PM, Guchun Chen wrote:
>> VCN instance 1 is power gated permanently by SMU.
>>
>> Bug: https://gitlab.freedesktop.org/drm/amd/-/issues/1743
>>
>> Fixes: f6b6d7d6bc2d("drm/amdgpu/vcn: remove manual instance setting")
> 
> Nice find. Looking at the fix, the logic is already broken by
> 5e26e52adb46("drm/amdgpu/vcn3.0: convert to IP version checking")
> 
> Any ASIC other than Sienna which has same VCN IP version (3.0.0) may be broken. Any more extra checks?
> 
> Thanks,
> Lijo
> 
>> Signed-off-by: Guchun Chen <guchun.chen at amd.com>
>> ---
>>    drivers/gpu/drm/amd/amdgpu/vcn_v3_0.c | 9 +++++++++
>>    1 file changed, 9 insertions(+)
>>
>> diff --git a/drivers/gpu/drm/amd/amdgpu/vcn_v3_0.c
>> b/drivers/gpu/drm/amd/amdgpu/vcn_v3_0.c
>> index dbfd92984655..4848922667f2 100644
>> --- a/drivers/gpu/drm/amd/amdgpu/vcn_v3_0.c
>> +++ b/drivers/gpu/drm/amd/amdgpu/vcn_v3_0.c
>> @@ -103,6 +103,15 @@ static int vcn_v3_0_early_init(void *handle)
>>    			adev->vcn.num_enc_rings = 0;
>>    		else
>>    			adev->vcn.num_enc_rings = 2;
>> +
>> +		/*
>> +		 * Fix ME.
>> +		 * VCN instance number is limited to 1 for below ASIC due to
>> +		 * VCN instnace 1 is permanently power gated.
>> +		 */
>> +		if ((adev->ip_versions[UVD_HWIP][0] == IP_VERSION(3, 0, 0)) &&
>> +			(adev->ip_versions[GC_HWIP][0] == IP_VERSION(10, 3, 2)))
>> +			adev->vcn.num_vcn_inst = 1;
>>    	}
>>    
>>    	vcn_v3_0_set_dec_ring_funcs(adev);
>>