drm/i915/dp_mst: Disable Panel Replay

[ Upstream commit f2687d3 ]

Disable Panel Replay on MST links until it's properly implemented. For
instance the required VSC SDP is not programmed on MST and FEC is not
enabled if Panel Replay is enabled.

Fixes: 3257e55 ("drm/i915/panelreplay: enable/disable panel replay")
Closes: https://gitlab.freedesktop.org/drm/i915/kernel/-/issues/15174
Cc: Jouni Högander <jouni.hogander@intel.com>
Cc: Animesh Manna <animesh.manna@intel.com>
Cc: stable@vger.kernel.org # v6.8+
Reviewed-by: Jouni Högander <jouni.hogander@intel.com>
Signed-off-by: Imre Deak <imre.deak@intel.com>
Link: https://patch.msgid.link/20251107124141.911895-1-imre.deak@intel.com
(cherry picked from commit e109f64)
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
[ placed MST check at function start since DPCD read was moved to caller ]
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Author: ideak

drivers/gpu/drm/i915/display/intel_psr.c

@@ -591,6 +591,10 @@ static void _panel_replay_init_dpcd(struct intel_dp *intel_dp)
 {
 	struct intel_display *display = to_intel_display(intel_dp);
 
+	/* TODO: Enable Panel Replay on MST once it's properly implemented. */
+	if (intel_dp->mst_detect == DRM_DP_MST)
+		return;
+
 	if (intel_dp_is_edp(intel_dp)) {
 		if (!intel_alpm_aux_less_wake_supported(intel_dp)) {
 			drm_dbg_kms(display->drm,