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

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

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