Add get function for silence period and lfps half cycle. Values are taken
from the tables in bspec.
Bspec: 71632
v3:
- use PORT_ALPM_CTL_SILENCE_PERIOD_MASK instead of value 255
- use PORT_ALPM_LFPS_CTL_LAST_LFPS_HALF_CYCLE_DURATION_MASK instead of
value 31
v2:
- fix some checks
- add some more comments
Signed-off-by: Jouni Högander <jouni.hogan...@intel.com>
---
.../drm/i915/display/intel_display_types.h | 2 +
drivers/gpu/drm/i915/display/intel_psr.c | 82 ++++++++++++++++++-
2 files changed, 82 insertions(+), 2 deletions(-)
diff --git a/drivers/gpu/drm/i915/display/intel_display_types.h
b/drivers/gpu/drm/i915/display/intel_display_types.h
index 8a35fb6b2ade..c2ce80bd3cb9 100644
--- a/drivers/gpu/drm/i915/display/intel_display_types.h
+++ b/drivers/gpu/drm/i915/display/intel_display_types.h
@@ -1743,6 +1743,8 @@ struct intel_psr {
/* LNL and beyond */
u8 check_entry_lines;
+ u8 silence_period_sym_clocks;
+ u8 lfps_half_cycle_num_of_syms;
} alpm_parameters;
ktime_t last_entry_attempt;
diff --git a/drivers/gpu/drm/i915/display/intel_psr.c
b/drivers/gpu/drm/i915/display/intel_psr.c
index bfe320bcefef..9be8bf3fe651 100644
--- a/drivers/gpu/drm/i915/display/intel_psr.c
+++ b/drivers/gpu/drm/i915/display/intel_psr.c
@@ -1126,6 +1126,74 @@ static bool
_compute_psr2_sdp_prior_scanline_indication(struct intel_dp *intel_d
return true;
}
+/*
+ * 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
+ * FLOOR( (Link Rate * tLFPS_Cycle) / (2 * 10) )
+ *
+ * Link rates 5.4 - 8.1
+ * PORT_ALPM_LFPS_CTL[ LFPS Cycle Count ] = 10
+ * LFPS Period chosen is the mid-point of the min:max values from the table
+ * 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)
+{
+ 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;
+ return false;
+ }
+ return true;
+}
+
/*
* AUX-Less Wake Time = CEILING( ((PHY P2 to P0) + tLFPS_Period, Max+
* tSilence, Max+ tPHY Establishment + tCDS) / tline)
@@ -1165,20 +1233,30 @@ static int _lnl_compute_aux_less_alpm_params(struct
intel_dp *intel_dp,
struct intel_crtc_state
*crtc_state)
{
struct drm_i915_private *i915 = dp_to_i915(intel_dp);
- int aux_less_wake_time, aux_less_wake_lines;
+ int aux_less_wake_time, aux_less_wake_lines, silence_period,
+ lfps_half_cycle;
aux_less_wake_time =
_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 (aux_less_wake_lines > ALPM_CTL_AUX_LESS_WAKE_TIME_MASK)
+ if (!_lnl_get_silence_period_and_lfps_half_cycle(intel_dp->link_rate,
+ &silence_period,
+ &lfps_half_cycle))
+ return false;
+
+ if (aux_less_wake_lines > ALPM_CTL_AUX_LESS_WAKE_TIME_MASK ||
+ silence_period > PORT_ALPM_CTL_SILENCE_PERIOD_MASK ||
+ lfps_half_cycle >
PORT_ALPM_LFPS_CTL_LAST_LFPS_HALF_CYCLE_DURATION_MASK)
return false;
if (i915->display.params.psr_safest_params)
aux_less_wake_lines = ALPM_CTL_AUX_LESS_WAKE_TIME_MASK;
intel_dp->psr.alpm_parameters.fast_wake_lines = aux_less_wake_lines;
+ intel_dp->psr.alpm_parameters.silence_period_sym_clocks =
silence_period;
+ intel_dp->psr.alpm_parameters.lfps_half_cycle_num_of_syms =
lfps_half_cycle;
return true;
}
--
2.34.1
