drm/i915: Disable port sync when bigjoiner is used

commit 0653d50 upstream.

The current modeset sequence can't handle port sync and bigjoiner
at the same time. Refuse port sync when bigjoiner is needed,
at least until we fix the modeset sequence.

v2: Add a FIXME (Vandite)

Cc: stable@vger.kernel.org
Tested-by: Vidya Srinivas <vidya.srinivas@intel.com>
Reviewed-by: Vandita Kulkarni <vandita.kulkarni@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240404213441.17637-4-ville.syrjala@linux.intel.com
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
(cherry picked from commit b37e1347b991459c38c56ec2476087854a4f720b)
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

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

@@ -4111,7 +4111,12 @@ static bool m_n_equal(const struct intel_link_m_n *m_n_1,
 static bool crtcs_port_sync_compatible(const struct intel_crtc_state *crtc_state1,
 				       const struct intel_crtc_state *crtc_state2)
 {
+	/*
+	 * FIXME the modeset sequence is currently wrong and
+	 * can't deal with bigjoiner + port sync at the same time.
+	 */
 	return crtc_state1->hw.active && crtc_state2->hw.active &&
+		!crtc_state1->bigjoiner_pipes && !crtc_state2->bigjoiner_pipes &&
 		crtc_state1->output_types == crtc_state2->output_types &&
 		crtc_state1->output_format == crtc_state2->output_format &&
 		crtc_state1->lane_count == crtc_state2->lane_count &&