[PATCH] drm/dp: retry AUX transactions 32 times (v1.1)

[Jani Nikula]

On Tue, 09 Dec 2014, Dave Airlie <airlied at gmail.com> wrote:
>> Missed this version, see my reply to v1:
>> http://mid.gmane.org/87k32iqppg.fsf@intel.com
>>
>> Also, what if you avoid sink dpms off with:
>>
>> diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
>> index 70bb8d0b9695..768b1bfaea78 100644
>> --- a/drivers/gpu/drm/i915/intel_dp.c
>> +++ b/drivers/gpu/drm/i915/intel_dp.c
>> @@ -1932,7 +1932,7 @@ void intel_dp_sink_dpms(struct intel_dp *intel_dp, int mode)
>>
>>         if (mode != DRM_MODE_DPMS_ON) {
>>                 ret = drm_dp_dpcd_writeb(&intel_dp->aux, DP_SET_POWER,
>> -                                        DP_SET_POWER_D3);
>> +                                        DP_SET_POWER_D0);
>>         } else {
>>                 /*
>>                  * When turning on, we need to retry for 1ms to give the sink
>>
>> Does it make a difference?
>
> Meant to reply, but the sink is definitely out of dpms when hit this,
>
> I've already done a fair few dpcd transactions, and asked it to link train,
> It is mostly link training the downstream at that point that I think is making
> it defer.

Okay, ack on the patch then. I wish we had something better to base the
limit on, but if this makes it work, so be it.

BR,
Jani.


>
> Dave.

-- 
Jani Nikula, Intel Open Source Technology Center