[PATCH 1/4] drm/i915/psr: Add new function for writing sink panel replay enable bit

["Jouni Högander" <jouni.hogander@intel.com>]

According to DP/eDP specification only DP_PANEL_REPLAY_ENABLE has to be set
prior link training. For this purpose add a new function which sets this
bit on sink side if Panel Replay is supported by the sink and the source.

Signed-off-by: Jouni Högander <jouni.hogander@intel.com>
---
 drivers/gpu/drm/i915/display/intel_psr.c | 7 +++++++
 drivers/gpu/drm/i915/display/intel_psr.h | 1 +
 2 files changed, 8 insertions(+)

diff --git a/drivers/gpu/drm/i915/display/intel_psr.c b/drivers/gpu/drm/i915/display/intel_psr.c
index 64c00a8a6850..e592bc01c7fb 100644
--- a/drivers/gpu/drm/i915/display/intel_psr.c
+++ b/drivers/gpu/drm/i915/display/intel_psr.c
@@ -827,6 +827,13 @@ void intel_psr_enable_sink(struct intel_dp *intel_dp,
 		drm_dp_dpcd_writeb(&intel_dp->aux, DP_SET_POWER, DP_SET_POWER_D0);
 }
 
+void intel_psr_panel_replay_enable_sink(struct intel_dp *intel_dp)
+{
+	if (CAN_PANEL_REPLAY(intel_dp))
+		drm_dp_dpcd_writeb(&intel_dp->aux, PANEL_REPLAY_CONFIG,
+				   DP_PANEL_REPLAY_ENABLE);
+}
+
 static u32 intel_psr1_get_tp_time(struct intel_dp *intel_dp)
 {
 	struct intel_display *display = to_intel_display(intel_dp);
diff --git a/drivers/gpu/drm/i915/display/intel_psr.h b/drivers/gpu/drm/i915/display/intel_psr.h
index 956be263c09e..3b2643b83e06 100644
--- a/drivers/gpu/drm/i915/display/intel_psr.h
+++ b/drivers/gpu/drm/i915/display/intel_psr.h
@@ -30,6 +30,7 @@ bool intel_psr_needs_aux_io_power(struct intel_encoder *encoder,
 void intel_psr_init_dpcd(struct intel_dp *intel_dp);
 void intel_psr_enable_sink(struct intel_dp *intel_dp,
 			   const struct intel_crtc_state *crtc_state);
+void intel_psr_panel_replay_enable_sink(struct intel_dp *intel_dp);
 void intel_psr_pre_plane_update(struct intel_atomic_state *state,
 				struct intel_crtc *crtc);
 void intel_psr_post_plane_update(struct intel_atomic_state *state,
-- 
2.34.1