[PATCH 3/6] drm/i915/psr: Calculate aux less switch to active latency

[Jouni Högander]

Calculate aux less  switch to active latency and store it into alpm_params
struct.

Bspec: 71477

Signed-off-by: Jouni Högander <jouni.hogan...@intel.com>
---
 .../drm/i915/display/intel_display_types.h    |  1 +
 drivers/gpu/drm/i915/display/intel_psr.c      | 26 ++++++++++++++++---
 2 files changed, 24 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/i915/display/intel_display_types.h 
b/drivers/gpu/drm/i915/display/intel_display_types.h
index a531c1e5af20..df82551a3f42 100644
--- a/drivers/gpu/drm/i915/display/intel_display_types.h
+++ b/drivers/gpu/drm/i915/display/intel_display_types.h
@@ -1722,6 +1722,7 @@ struct intel_psr {
                /* LNL and beyond */
                u8 check_entry_lines;
                u8 aux_less_wake_lines;
+               u8 switch_to_active_lines;
        } 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 b139db67df55..4cefb9ada5db 100644
--- a/drivers/gpu/drm/i915/display/intel_psr.c
+++ b/drivers/gpu/drm/i915/display/intel_psr.c
@@ -1154,24 +1154,44 @@ static int _lnl_compute_aux_less_wake_time(int 
port_clock)
                            num_ml_phy_lock * tml_phy_lock, 1000);
 }
 
+/*
+ * 128b/132b Switch to Active = 32 * (ML_PHY_LOCK Length + 3 + 64) / fLink (in 
MHz)
+ * Switch to Active Latency = CEILING( t128b/132b Switch to Active / tLine )
+ * ML_PHY_LOCK Length = 396
+ * The "+3" term is the trailing zero padding after the POST_LT_SCRAMBLER_RESET
+ * The "+64" term represents the MTP timeslots
+ */
+static int _lnl_compute_switch_to_active_time(int port_clock)
+{
+       return 32 * (396 + 3 + 64) / (port_clock / 1000);
+}
+
 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, switch_to_active_lines;
 
        aux_less_wake_time =
                _lnl_compute_aux_less_wake_time(crtc_state->port_clock / 1000);
        aux_less_wake_lines = 
intel_usecs_to_scanlines(&crtc_state->hw.adjusted_mode,
                                                       aux_less_wake_time);
 
-       if (aux_less_wake_lines > 32)
+       switch_to_active_lines =
+               intel_usecs_to_scanlines(
+                       &crtc_state->hw.adjusted_mode,
+                       
_lnl_compute_switch_to_active_time(crtc_state->port_clock / 1000));
+
+       if (aux_less_wake_lines > 32 || switch_to_active_lines > 32)
                return false;
 
-       if (i915->display.params.psr_safest_params)
+       if (i915->display.params.psr_safest_params) {
                aux_less_wake_lines = 32;
+               switch_to_active_lines = 32;
+       }
 
        intel_dp->psr.alpm_parameters.aux_less_wake_lines = aux_less_wake_lines;
+       intel_dp->psr.alpm_parameters.switch_to_active_lines = 
switch_to_active_lines;
 
        return true;
 }
-- 
2.34.1