[PATCH] drm/amdgpu: Retry i2c transfer once if it fails on SMU13.0.6

[Lazar, Lijo]

On 9/12/2024 2:42 AM, Russell, Kent wrote:
> [AMD Official Use Only - AMD Internal Distribution Only]
> 
> [AMD Official Use Only - AMD Internal Distribution Only]
> 
> Fixed the typo locally.
> 
>> -----Original Message-----
>> From: Russell, Kent <Kent.Russell at amd.com>
>> Sent: Wednesday, September 11, 2024 2:06 PM
>> To: amd-gfx at lists.freedesktop.org
>> Cc: Russell, Kent <Kent.Russell at amd.com>
>> Subject: [PATCH] drm/amdgpu: Retry i2c transfer once if it fails on SMU13.0.6
>>
>> During init, there can be some collisions on the i2c bus that result in
>> the EEPROM read failing. This has been mitigated in the PMFW to a
>> degree, but there is still a small chance that the bus will be busy.
>> When the read fails during RAS init, that disables page retirement
>> altogether, which is obviously not ideal. To try to avoid that
>> situation, set the eeprom_read function to retry once if the first read
>> fails, specifically for smu_v13_0_6.
>>
>> Signed-off-by: Kent Russell <kent.russell at amd.com>

	Reviewed-by: Lijo Lazar <lijo.lazar at amd.com>

Thanks,
Lijo

>> ---
>>  drivers/gpu/drm/amd/pm/swsmu/smu13/smu_v13_0_6_ppt.c | 8 ++++++--
>>  1 file changed, 6 insertions(+), 2 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/amd/pm/swsmu/smu13/smu_v13_0_6_ppt.c
>> b/drivers/gpu/drm/amd/pm/swsmu/smu13/smu_v13_0_6_ppt.c
>> index 9974c9f8135e..65d24c2f7e24 100644
>> --- a/drivers/gpu/drm/amd/pm/swsmu/smu13/smu_v13_0_6_ppt.c
>> +++ b/drivers/gpu/drm/amd/pm/swsmu/smu13/smu_v13_0_6_ppt.c
>> @@ -2107,8 +2107,12 @@ static int smu_v13_0_6_i2c_xfer(struct i2c_adapter
>> *i2c_adap,
>>       }
>>       mutex_lock(&adev->pm.mutex);
>>       r = smu_v13_0_6_request_i2c_xfer(smu, req);
>> -     if (r)
>> -             goto fail;
>> +     if (r) {
>> +             /* Rrtry once, in case of an i2c collision */
> Rrtry->Retry
>> +             r = smu_v13_0_6_request_i2c_xfer(smu, req);
>> +             if (r)
>> +                     goto fail;
>> +     }
>>
>>       for (c = i = 0; i < num_msgs; i++) {
>>               if (!(msg[i].flags & I2C_M_RD)) {
>> --
>> 2.34.1
>