drm/i915/psr: Apply Intel DPCD workaround when SDP on prior line used

From Jouni Hogander
487393023feb57ce5305e00eaae21dd50520f3d0 in linux-6.18.y/6.18.35
4703049f768fc1c1caac754134118bee1a3af189 in mainline linux

sys/dev/pci/drm/i915/display/intel_psr.c

@@ -29,6 +29,7 @@
 #include <drm/drm_vblank.h>
 
 #include "i915_reg.h"
+#include "i915_utils.h"
 #include "intel_alpm.h"
 #include "intel_atomic.h"
 #include "intel_crtc.h"
@@ -1315,6 +1316,30 @@ static bool psr2_granularity_check(struct intel_dp *intel_dp,
 	return true;
 }
 
+static bool apply_scanline_indication_wa(struct intel_dp *intel_dp,
+					 struct intel_crtc_state *crtc_state)
+{
+	u8 early_scanline_support = intel_dp->intel_wa_dpcd &
+		INTEL_DPCD_INTEL_WA_REGISTER_CAPS_PSR2_EARLYSCANLINE_SDP_SUPPORT_MASK;
+
+	if (intel_dp->edp_dpcd[0] >= DP_EDP_15)
+		return true;
+
+	switch (early_scanline_support)	{
+	case INTEL_DPCD_INTEL_WA_REGISTER_CAPS_FALL_BACK_TO_PSR1:
+		crtc_state->req_psr2_sdp_prior_scanline = false;
+		return false;
+	case INTEL_DPCD_INTEL_WA_REGISTER_CAPS_PSR2_WITH_EARLY_SCANLINE:
+		return true;
+	case INTEL_DPCD_INTEL_WA_REGISTER_CAPS_PSR2_WITHOUT_EARLY_SCANLINE:
+		crtc_state->req_psr2_sdp_prior_scanline = false;
+		return true;
+	default:
+		MISSING_CASE(early_scanline_support);
+		return false;
+	}
+}
+
 static bool _compute_psr2_sdp_prior_scanline_indication(struct intel_dp *intel_dp,
 							struct intel_crtc_state *crtc_state)
 {
@@ -1336,7 +1361,8 @@ static bool _compute_psr2_sdp_prior_scanline_indication(struct intel_dp *intel_d
 		return false;
 
 	crtc_state->req_psr2_sdp_prior_scanline = true;
-	return true;
+
+	return apply_scanline_indication_wa(intel_dp, crtc_state);
 }
 
 static int intel_psr_entry_setup_frames(struct intel_dp *intel_dp,