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

[Taylor, Clinton A]

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