[PATCH 6.19 623/844] drm/i915/psr: Don't enable Panel Replay on sink if globally disabled

[Sasha Levin]

From: Jouni Högander <jouni.hogander@xxxxxxxxx>

[ Upstream commit 69f83f167463bad26104af7fbc114ce1f80366b0 ]

With some panels informing support for Panel Replay we are observing
problems if having Panel Replay enable bit set on sink when forced to use
PSR instead of Panel Replay. Avoid these problems by not setting Panel
Replay enable bit in sink when Panel Replay is globally disabled during
link training. I.e. disabled by module parameter.

The enable bit is still set when disabling Panel Replay via debugfs
interface. Added note comment about this.

Fixes: 68f3a505b367 ("drm/i915/psr: Enable Panel Replay on sink always when it's supported")
Cc: Mika Kahola <mika.kahola@xxxxxxxxx>
Cc: Jani Nikula <jani.nikula@xxxxxxxxxxxxxxx>
Cc: Rodrigo Vivi <rodrigo.vivi@xxxxxxxxx>
Cc: <stable@xxxxxxxxxxxxxxx> # v6.15+
Signed-off-by: Jouni Högander <jouni.hogander@xxxxxxxxx>
Reviewed-by: Mika Kahola <mika.kahola@xxxxxxxxx>
Link: https://patch.msgid.link/20260115070039.368965-1-jouni.hogander@xxxxxxxxx
(cherry picked from commit c5a52cd04e24f0ae53fda26f74ab027b8c548e0e)
Signed-off-by: Joonas Lahtinen <joonas.lahtinen@xxxxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 drivers/gpu/drm/i915/display/intel_psr.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/i915/display/intel_psr.c b/drivers/gpu/drm/i915/display/intel_psr.c
index 08bca45739749..44063b578354e 100644
--- a/drivers/gpu/drm/i915/display/intel_psr.c
+++ b/drivers/gpu/drm/i915/display/intel_psr.c
@@ -857,7 +857,12 @@ static void intel_psr_enable_sink(struct intel_dp *intel_dp,
 
 void intel_psr_panel_replay_enable_sink(struct intel_dp *intel_dp)
 {
-	if (CAN_PANEL_REPLAY(intel_dp))
+	/*
+	 * NOTE: We might want to trigger mode set when
+	 * disabling/enabling Panel Replay via debugfs interface to
+	 * ensure this bit is cleared/set accordingly.
+	 */
+	if (CAN_PANEL_REPLAY(intel_dp) && panel_replay_global_enabled(intel_dp))
 		drm_dp_dpcd_writeb(&intel_dp->aux, PANEL_REPLAY_CONFIG,
 				   DP_PANEL_REPLAY_ENABLE);
 }
-- 
2.51.0