Re: [PATCH] drm/i915/display/dp: Reduce log level for SOURCE OUI write failures

["Pottumuttu, Sai Teja" <sai.teja.pottumuttu@intel.com>]

On 17-10-2024 01:12, Taylor, Clinton A wrote:
> On Fri, 2024-10-11 at 12:34 +0530, Pottumuttu, Sai Teja wrote:
>> On 11-10-2024 03:00, Taylor, Clinton A wrote:
>>> On Wed, 2024-10-09 at 22:32 +0530, Pottumuttu, Sai Teja wrote:
>>>> On 05-10-2024 02:38, Clint Taylor wrote:
>>>>> Some devices NAK DPCD writes to the SOURCE OUI (0x300) DPCD registers.
>>>>> Reduce the log level priority to prevent dmesg noise for these devices.
>>>>>
>>>>> Signed-off-by: Clint Taylor <clinton.a.taylor@intel.com>
>>>>> ---
>>>>>     drivers/gpu/drm/i915/display/intel_dp.c | 2 +-
>>>>>     1 file changed, 1 insertion(+), 1 deletion(-)
>>>>>
>>>>> diff --git a/drivers/gpu/drm/i915/display/intel_dp.c
>>>>> b/drivers/gpu/drm/i915/display/intel_dp.c
>>>>> index fbb096be02ad..9920ec1f9c53 100644
>>>>> --- a/drivers/gpu/drm/i915/display/intel_dp.c
>>>>> +++ b/drivers/gpu/drm/i915/display/intel_dp.c
>>>>> @@ -3418,7 +3418,7 @@ intel_edp_init_source_oui(struct intel_dp *intel_dp, bool
>>>>> careful)
>>>>>     	}
>>>>>     
>>>>>     	if (drm_dp_dpcd_write(&intel_dp->aux, DP_SOURCE_OUI, oui, sizeof(oui)) <
>>>>> 0)
>>>>> -		drm_err(&i915->drm, "Failed to write source OUI\n");
>>>>> +		drm_info(&i915->drm, "Failed to write source OUI\n");
>>>>>     
>>>> Just had one small question here, I think NAK is one case, but in case
>>>> of other errors/failures (EINVAL, ENOMEM) would we still want to reduce
>>>> the log level?
>>> If EINVAL or ENOMEM occurs there will be plenty of other failures earlier and later
>>> that
>>> will be logged. This function returns void so we don't handle any failure for
>>> SourceOUI
>>> write anyway. This just prevents noise in the dmesg log from known devices that NAK
>>> this
>>> particular DPCD operation. The other option would be to list all known devices that
>>> return
>>> NAK and filter them via a DCPD quirk.
>>>
>>> -Clint
>> Ok, in that case, should we also consider decreasing the log level of
>> read failure a little above?
> Read response should never be NAK'd by the Sink device.
>
> -Clint
>   

Thanks for the clarification, with that,

Reviewed-by: Sai Teja Pottumuttu <sai.teja.pottumuttu@intel.com>

Thanks,
Sai Teja

>>>     
>>>> Thanks,
>>>> Sai Teja
>>>>
>>>>>     	intel_dp->last_oui_write = jiffies;
>>>>>     }