UBUNTU: SAUCE: drm/i915/display/psr: Disable DC3CO when the PSR2 is used

BugLink: https://bugs.launchpad.net/bugs/1922885

Due to the changed sequence of activating/deactivating DC3CO, disable
DC3CO until the changed dc3co activating/deactivating sequence is applied.

References: https://gitlab.freedesktop.org/drm/intel/-/issues/3134
Signed-off-by: Gwan-gyeong Mun <gwan-gyeong.mun@intel.com>
Reviewed-by: José Roberto de Souza <jose.souza@intel.com>
Signed-off-by: José Roberto de Souza <jose.souza@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210401170237.40472-1-gwan-gyeong.mun@intel.com
(cherry picked from commit 2d66744
git://anongit.freedesktop.org/drm-intel drm-intel-next)
Signed-off-by: Hui Wang <hui.wang@canonical.com>
Signed-off-by: Timo Aaltonen <timo.aaltonen@canonical.com>

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

@@ -658,6 +658,13 @@ tgl_dc3co_exitline_compute_config(struct intel_dp *intel_dp,
 	struct drm_i915_private *dev_priv = dp_to_i915(intel_dp);
 	u32 exit_scanlines;
 
+	/*
+	 * FIXME: Due to the changed sequence of activating/deactivating DC3CO,
+	 * disable DC3CO until the changed dc3co activating/deactivating sequence
+	 * is applied. B.Specs:49196
+	 */
+	return;
+
 	/*
 	 * DMC's DC3CO exit mechanism has an issue with Selective Fecth
 	 * TODO: when the issue is addressed, this restriction should be removed.