drm/i915/display: Wait at least 2 frames before selective update

BSpec states that the minimum number of frames before selective update
is 2, so making sure this minimum limit is fulfilled.

BSpec: 50422
Reviewed-by: Gwan-gyeong Mun <gwan-gyeong.mun@intel.com>
Cc: Gwan-gyeong Mun <gwan-gyeong.mun@intel.com>
Signed-off-by: José Roberto de Souza <jose.souza@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210914212507.177511-2-jose.souza@intel.com

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

@@ -510,7 +510,7 @@ static void hsw_activate_psr2(struct intel_dp *intel_dp)
 	if (DISPLAY_VER(dev_priv) >= 10 && DISPLAY_VER(dev_priv) <= 12)
 		val |= EDP_Y_COORDINATE_ENABLE;
 
-	val |= EDP_PSR2_FRAME_BEFORE_SU(intel_dp->psr.sink_sync_latency + 1);
+	val |= EDP_PSR2_FRAME_BEFORE_SU(max_t(u8, intel_dp->psr.sink_sync_latency + 1, 2));
 	val |= intel_psr2_get_tp_time(intel_dp);
 
 	/* Wa_22012278275:adl-p */