[Intel-gfx] [PATCH 2/7] drm/i915/mst: abstract intel_dp_ack_sink_irq_esi()

[Jani Nikula]

On Thu, 20 Jan 2022, "Shankar, Uma" <uma.shankar at intel.com> wrote:
>> -----Original Message-----
>> From: Intel-gfx <intel-gfx-bounces at lists.freedesktop.org> On Behalf Of Jani Nikula
>> Sent: Tuesday, January 4, 2022 11:10 PM
>> To: intel-gfx at lists.freedesktop.org
>> Cc: Nikula, Jani <jani.nikula at intel.com>
>> Subject: [Intel-gfx] [PATCH 2/7] drm/i915/mst: abstract intel_dp_ack_sink_irq_esi()
>> 
>> Smaller functions make the thing easier to read. Debug log failures to ack.
>> 
>> Note: Looks like we have the retry loop simply because of hysterical raisins, dating
>
> Nit: Typo in reasons.

;)

http://www.catb.org/jargon/html/H/hysterical-reasons.html

>
> Reviewed-by: Uma Shankar <uma.shankar at intel.com>
>
>> back to the original DP MST enabling. Keep it, though I have no idea why we have it.
>> 
>> Signed-off-by: Jani Nikula <jani.nikula at intel.com>
>> ---
>>  drivers/gpu/drm/i915/display/intel_dp.c | 25 +++++++++++++++----------
>>  1 file changed, 15 insertions(+), 10 deletions(-)
>> 
>> diff --git a/drivers/gpu/drm/i915/display/intel_dp.c
>> b/drivers/gpu/drm/i915/display/intel_dp.c
>> index 357c39e09bf6..ebf80a875a41 100644
>> --- a/drivers/gpu/drm/i915/display/intel_dp.c
>> +++ b/drivers/gpu/drm/i915/display/intel_dp.c
>> @@ -2820,6 +2820,19 @@ intel_dp_get_sink_irq_esi(struct intel_dp *intel_dp, u8
>> *sink_irq_vector)
>>  		DP_DPRX_ESI_LEN;
>>  }
>> 
>> +static bool intel_dp_ack_sink_irq_esi(struct intel_dp *intel_dp, u8
>> +esi[4]) {
>> +	int retry;
>> +
>> +	for (retry = 0; retry < 3; retry++) {
>> +		if (drm_dp_dpcd_write(&intel_dp->aux, DP_SINK_COUNT_ESI + 1,
>> +				      &esi[1], 3) == 3)
>> +			return true;
>> +	}
>> +
>> +	return false;
>> +}
>> +
>>  bool
>>  intel_dp_needs_vsc_sdp(const struct intel_crtc_state *crtc_state,
>>  		       const struct drm_connector_state *conn_state) @@ -3660,7
>> +3673,6 @@ intel_dp_check_mst_status(struct intel_dp *intel_dp)
>>  		 */
>>  		u8 esi[DP_DPRX_ESI_LEN+2] = {};
>>  		bool handled;
>> -		int retry;
>> 
>>  		if (!intel_dp_get_sink_irq_esi(intel_dp, esi)) {
>>  			drm_dbg_kms(&i915->drm,
>> @@ -3685,15 +3697,8 @@ intel_dp_check_mst_status(struct intel_dp *intel_dp)
>>  		if (!handled)
>>  			break;
>> 
>> -		for (retry = 0; retry < 3; retry++) {
>> -			int wret;
>> -
>> -			wret = drm_dp_dpcd_write(&intel_dp->aux,
>> -						 DP_SINK_COUNT_ESI+1,
>> -						 &esi[1], 3);
>> -			if (wret == 3)
>> -				break;
>> -		}
>> +		if (!intel_dp_ack_sink_irq_esi(intel_dp, esi))
>> +			drm_dbg_kms(&i915->drm, "Failed to ack ESI\n");
>>  	}
>> 
>>  	return link_ok;
>> --
>> 2.30.2
>

-- 
Jani Nikula, Intel Open Source Graphics Center