Commit 3b5b2567 authored by Jouni Högander's avatar Jouni Högander
Browse files

drm/i915/alpm: Calculate silence period 



Calculate silence period instead of hardcoding it in switch case.

Signed-off-by: default avatarJouni Högander <jouni.hogander@intel.com>
Reviewed-by: default avatarAnimesh Manna <animesh.manna@intel.com>
Link: https://lore.kernel.org/r/20250829053929.3585636-2-jouni.hogander@intel.com
parent f7e60f15

drivers/gpu/drm/i915/display/intel_alpm.c

+17 −20
Original line number Diff line number Diff line
@@ -16,6 +16,12 @@ 
#include "intel_psr.h"

#include "intel_psr_regs.h"



#define SILENCE_PERIOD_MIN_TIME	80

#define SILENCE_PERIOD_MAX_TIME	180

#define SILENCE_PERIOD_TIME	(SILENCE_PERIOD_MIN_TIME +	\

				(SILENCE_PERIOD_MAX_TIME -	\

				 SILENCE_PERIOD_MIN_TIME) / 2)



bool intel_alpm_aux_wake_supported(struct intel_dp *intel_dp)

{

	return intel_dp->alpm_dpcd & DP_ALPM_CAP;
@@ -44,11 +50,15 @@ void intel_alpm_init(struct intel_dp *intel_dp) 
	mutex_init(&intel_dp->alpm_parameters.lock);

}



static int get_silence_period_symbols(const struct intel_crtc_state *crtc_state)

{

	return SILENCE_PERIOD_TIME * intel_dp_link_symbol_clock(crtc_state->port_clock) /

		1000 / 1000;

}



/*

 * See Bspec: 71632 for the table

 *

 * Silence_period = tSilence,Min + ((tSilence,Max - tSilence,Min) / 2)

 *

 * Half cycle duration:

 *

 * Link rates 1.62 - 4.32 and tLFPS_Cycle = 70 ns
@@ -60,53 +70,41 @@ void intel_alpm_init(struct intel_dp *intel_dp) 
 * FLOOR( LFPS Period in Symbol clocks /

 * (2 * PORT_ALPM_LFPS_CTL[ LFPS Cycle Count ]) )

 */

static bool _lnl_get_silence_period_and_lfps_half_cycle(int link_rate,

							int *silence_period,

							int *lfps_half_cycle)

static bool _lnl_get_lfps_half_cycle(int link_rate, int *lfps_half_cycle)

{

	switch (link_rate) {

	case 162000:

		*silence_period = 20;

		*lfps_half_cycle = 5;

		break;

	case 216000:

		*silence_period = 27;

		*lfps_half_cycle = 7;

		break;

	case 243000:

		*silence_period = 31;

		*lfps_half_cycle = 8;

		break;

	case 270000:

		*silence_period = 34;

		*lfps_half_cycle = 9;

		break;

	case 324000:

		*silence_period = 41;

		*lfps_half_cycle = 11;

		break;

	case 432000:

		*silence_period = 56;

		*lfps_half_cycle = 15;

		break;

	case 540000:

		*silence_period = 69;

		*lfps_half_cycle = 12;

		break;

	case 648000:

		*silence_period = 84;

		*lfps_half_cycle = 15;

		break;

	case 675000:

		*silence_period = 87;

		*lfps_half_cycle = 15;

		break;

	case 810000:

		*silence_period = 104;

		*lfps_half_cycle = 19;

		break;

	default:

		*silence_period = *lfps_half_cycle = -1;

		*lfps_half_cycle = -1;

		return false;

	}

	return true;
@@ -160,9 +158,8 @@ _lnl_compute_aux_less_alpm_params(struct intel_dp *intel_dp, 
		_lnl_compute_aux_less_wake_time(crtc_state->port_clock);

	aux_less_wake_lines = intel_usecs_to_scanlines(&crtc_state->hw.adjusted_mode,

						       aux_less_wake_time);



	if (!_lnl_get_silence_period_and_lfps_half_cycle(crtc_state->port_clock,

							 &silence_period,

	silence_period = get_silence_period_symbols(crtc_state);

	if (!_lnl_get_lfps_half_cycle(crtc_state->port_clock,

				      &lfps_half_cycle))

		return false;