Unused bandwidth can be used by external display agents for Panel Replay
enabled DP panel during idleness with link on. Enable source to replace
dummy data from the display with data from another agent by programming
TRANS_DP2_CTL [Panel Replay Tunneling Enable].

Bspec: 68920
Signed-off-by: Animesh Manna <[email protected]>
---
 .../gpu/drm/i915/display/intel_display_regs.h |  1 +
 drivers/gpu/drm/i915/display/intel_psr.c      | 23 +++++++++++++++++++
 2 files changed, 24 insertions(+)

diff --git a/drivers/gpu/drm/i915/display/intel_display_regs.h 
b/drivers/gpu/drm/i915/display/intel_display_regs.h
index 9e0d853f4b61..b6fc249a9f09 100644
--- a/drivers/gpu/drm/i915/display/intel_display_regs.h
+++ b/drivers/gpu/drm/i915/display/intel_display_regs.h
@@ -2051,6 +2051,7 @@
 #define TRANS_DP2_CTL(trans)                   _MMIO_TRANS(trans, 
_TRANS_DP2_CTL_A, _TRANS_DP2_CTL_B)
 #define  TRANS_DP2_128B132B_CHANNEL_CODING     REG_BIT(31)
 #define  TRANS_DP2_PANEL_REPLAY_ENABLE         REG_BIT(30)
+#define  TRANS_DP2_PR_TUNNELING_ENABLE         REG_BIT(26)
 #define  TRANS_DP2_DEBUG_ENABLE                        REG_BIT(23)
 
 #define _TRANS_DP2_VFREQHIGH_A                 0x600a4
diff --git a/drivers/gpu/drm/i915/display/intel_psr.c 
b/drivers/gpu/drm/i915/display/intel_psr.c
index 2a378a5adc59..d0a01a08299e 100644
--- a/drivers/gpu/drm/i915/display/intel_psr.c
+++ b/drivers/gpu/drm/i915/display/intel_psr.c
@@ -44,6 +44,7 @@
 #include "intel_dmc.h"
 #include "intel_dp.h"
 #include "intel_dp_aux.h"
+#include "intel_dp_tunnel.h"
 #include "intel_dsb.h"
 #include "intel_frontbuffer.h"
 #include "intel_hdmi.h"
@@ -2152,6 +2153,25 @@ static bool psr_interrupt_error_check(struct intel_dp 
*intel_dp)
        return true;
 }
 
+static void intel_psr_set_pr_bw_optimization(struct intel_dp *intel_dp)
+{
+       struct intel_display *display = to_intel_display(intel_dp);
+       u8 val;
+
+       if (DISPLAY_VER(display) < 35)
+               return;
+
+       if (!intel_dp_tunnel_bw_alloc_is_enabled(intel_dp))
+               return;
+
+       drm_dp_dpcd_readb(&intel_dp->aux, DP_TUNNELING_CAPABILITIES, &val);
+       if (!(val & DP_PANEL_REPLAY_OPTIMIZATION_SUPPORT))
+               return;
+
+       intel_de_rmw(display, TRANS_DP2_CTL(intel_dp->psr.transcoder), 0,
+                    TRANS_DP2_PR_TUNNELING_ENABLE);
+}
+
 static void intel_psr_enable_locked(struct intel_dp *intel_dp,
                                    const struct intel_crtc_state *crtc_state)
 {
@@ -2221,6 +2241,9 @@ static void intel_psr_enable_locked(struct intel_dp 
*intel_dp,
        intel_dp->psr.link_ok = true;
 
        intel_psr_activate(intel_dp);
+
+       if (!intel_dp_is_edp(intel_dp) && intel_dp->psr.panel_replay_enabled)
+               intel_psr_set_pr_bw_optimization(intel_dp);
 }
 
 static void intel_psr_exit(struct intel_dp *intel_dp)
-- 
2.29.0

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