Re: [PATCH 12/19] drm/i915/psr: Write the PR config DPCDs in burst mode

["Nautiyal, Ankit K" <ankit.k.nautiyal@intel.com>]

On 3/13/2026 6:04 PM, Ville Syrjälä wrote:
> On Wed, Mar 11, 2026 at 05:06:04PM +0530, Ankit Nautiyal wrote:
>> Replace the consecutive single-byte writes to PANEL_REPLAY_CONFIG and
>> CONFIG2 with one drm_dp_dpcd_write() burst starting at PANEL_REPLAY_CONFIG,
>> reducing AUX transactions.
>>
>> Suggested-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
>> Signed-off-by: Ankit Nautiyal <ankit.k.nautiyal@intel.com>
>> ---
>>   drivers/gpu/drm/i915/display/intel_psr.c | 18 ++++++++++++------
>>   1 file changed, 12 insertions(+), 6 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/i915/display/intel_psr.c b/drivers/gpu/drm/i915/display/intel_psr.c
>> index 5041a5a138d1..ee6e26abd05e 100644
>> --- a/drivers/gpu/drm/i915/display/intel_psr.c
>> +++ b/drivers/gpu/drm/i915/display/intel_psr.c
>> @@ -774,27 +774,33 @@ static bool psr2_su_region_et_valid(struct intel_connector *connector, bool pane
>>   static void _panel_replay_enable_sink(struct intel_dp *intel_dp,
>>   				      const struct intel_crtc_state *crtc_state)
>>   {
>> -	u8 val = DP_PANEL_REPLAY_ENABLE |
>> +	struct intel_display *display = to_intel_display(intel_dp);
>> +	u8 panel_replay_config = DP_PANEL_REPLAY_ENABLE |
>>   		DP_PANEL_REPLAY_VSC_SDP_CRC_EN |
>>   		DP_PANEL_REPLAY_UNRECOVERABLE_ERROR_EN |
>>   		DP_PANEL_REPLAY_RFB_STORAGE_ERROR_EN |
>>   		DP_PANEL_REPLAY_ACTIVE_FRAME_CRC_ERROR_EN;
>>   	u8 panel_replay_config2 = DP_PANEL_REPLAY_CRC_VERIFICATION;
>> +	u8 buf[2];
> u8 panel_replay_config[2];
>
> would reduce the number of variables we have to contend with.


Makes sense. I will change as suggested in the next version.


>
>> +	int ret;
>>   
>>   	if (crtc_state->has_sel_update)
>> -		val |= DP_PANEL_REPLAY_SU_ENABLE;
>> +		panel_replay_config |= DP_PANEL_REPLAY_SU_ENABLE;
>>   
>>   	if (crtc_state->enable_psr2_su_region_et)
>> -		val |= DP_PANEL_REPLAY_ENABLE_SU_REGION_ET;
>> +		panel_replay_config |= DP_PANEL_REPLAY_ENABLE_SU_REGION_ET;
>>   
>>   	if (crtc_state->req_psr2_sdp_prior_scanline)
>>   		panel_replay_config2 |=
>>   			DP_PANEL_REPLAY_SU_REGION_SCANLINE_CAPTURE;
>>   
>> -	drm_dp_dpcd_writeb(&intel_dp->aux, PANEL_REPLAY_CONFIG, val);
>> +	buf[0] = panel_replay_config;
>> +	buf[1] = panel_replay_config2;
>> +
>> +	ret = drm_dp_dpcd_write(&intel_dp->aux, PANEL_REPLAY_CONFIG, buf, sizeof(buf));
>>   
>> -	drm_dp_dpcd_writeb(&intel_dp->aux, PANEL_REPLAY_CONFIG2,
>> -			   panel_replay_config2);
>> +	if (ret < 0 || ret != sizeof(buf))
> The < 0 check is redunadnt.

You are right, the other condition is sufficient. I will drop the 
redundant check.

Regards,
Ankit


>
>> +		drm_dbg_kms(display->drm, "Failed to write Panel Replay Configs\n");
>>   }
>>   
>>   static void _psr_enable_sink(struct intel_dp *intel_dp,
>> -- 
>> 2.45.2