[PATCH v1 4/6] drm/i915/vrr: Implement vblank evasion with DC balancing

[Mitul Golani]

Add vblank evasion logic when vrr is already enabled along with
dc balance is computed.

Signed-off-by: Ville Syrjälä <ville.syrjala at linux.intel.com>
---
 .../drm/i915/display/intel_display_types.h    |  2 +-
 drivers/gpu/drm/i915/display/intel_dsb.c      | 31 ++++++++++++++++++-
 drivers/gpu/drm/i915/display/intel_vblank.c   | 26 ++++++++++++++--
 3 files changed, 54 insertions(+), 5 deletions(-)

diff --git a/drivers/gpu/drm/i915/display/intel_display_types.h b/drivers/gpu/drm/i915/display/intel_display_types.h
index 94468a9d2e0d..0e06c71e9086 100644
--- a/drivers/gpu/drm/i915/display/intel_display_types.h
+++ b/drivers/gpu/drm/i915/display/intel_display_types.h
@@ -1303,7 +1303,7 @@ struct intel_crtc_state {
 
 	/* Variable Refresh Rate state */
 	struct {
-		bool enable, in_range;
+		bool enable, in_range, dc_balance;
 		u8 pipeline_full;
 		u16 flipline, vmin, vmax, guardband;
 		u32 vsync_end, vsync_start;
diff --git a/drivers/gpu/drm/i915/display/intel_dsb.c b/drivers/gpu/drm/i915/display/intel_dsb.c
index 72fe390c5af2..ed27cbff44fc 100644
--- a/drivers/gpu/drm/i915/display/intel_dsb.c
+++ b/drivers/gpu/drm/i915/display/intel_dsb.c
@@ -577,7 +577,36 @@ void intel_dsb_vblank_evade(struct intel_atomic_state *state,
 	if (crtc_state->has_psr)
 		intel_dsb_emit_wait_dsl(dsb, DSB_OPCODE_WAIT_DSL_OUT, 0, 0);
 
-	if (pre_commit_is_vrr_active(state, crtc)) {
+	if (pre_commit_is_vrr_active(state, crtc) && crtc_state->vrr.dc_balance) {
+		int vblank_delay = intel_vrr_vblank_delay(crtc_state);
+		int vmin_vblank_start, vmax_vblank_start;
+
+		vmin_vblank_start = intel_vrr_dcb_vmin_vblank_start_next(crtc_state);
+
+		if (vmin_vblank_start >= 0) {
+			end = vmin_vblank_start;
+			start = end - vblank_delay - latency;
+			intel_dsb_wait_scanline_out(state, dsb, start, end);
+		}
+
+		vmax_vblank_start = intel_vrr_dcb_vmax_vblank_start_next(crtc_state);
+
+		if (vmax_vblank_start >= 0) {
+			end = vmax_vblank_start;
+			start = end - vblank_delay - latency;
+			intel_dsb_wait_scanline_out(state, dsb, start, end);
+		}
+
+		vmin_vblank_start = intel_vrr_dcb_vmin_vblank_start_final(crtc_state);
+		end = vmin_vblank_start;
+		start = end - vblank_delay - latency;
+		intel_dsb_wait_scanline_out(state, dsb, start, end);
+
+		vmax_vblank_start = intel_vrr_dcb_vmax_vblank_start_final(crtc_state);
+		end = vmax_vblank_start;
+		start = end - vblank_delay - latency;
+		intel_dsb_wait_scanline_out(state, dsb, start, end);
+	} else if (pre_commit_is_vrr_active(state, crtc)) {
 		int vblank_delay = intel_vrr_vblank_delay(crtc_state);
 
 		end = intel_vrr_vmin_vblank_start(crtc_state);
diff --git a/drivers/gpu/drm/i915/display/intel_vblank.c b/drivers/gpu/drm/i915/display/intel_vblank.c
index 680013f00fc0..9b63e4217881 100644
--- a/drivers/gpu/drm/i915/display/intel_vblank.c
+++ b/drivers/gpu/drm/i915/display/intel_vblank.c
@@ -644,10 +644,30 @@ intel_pre_commit_crtc_state(struct intel_atomic_state *state,
 
 static int vrr_vblank_start(const struct intel_crtc_state *crtc_state)
 {
-	if (intel_vrr_is_push_sent(crtc_state))
-		return intel_vrr_vmin_vblank_start(crtc_state);
+	bool is_push_sent = intel_vrr_is_push_sent(crtc_state);
+	int vblank_start;
+
+	if (!crtc_state->vrr.dc_balance) {
+		if (is_push_sent)
+			return intel_vrr_vmin_vblank_start(crtc_state);
+		else
+			return intel_vrr_vmax_vblank_start(crtc_state);
+	}
+
+	if (is_push_sent)
+		vblank_start = intel_vrr_dcb_vmin_vblank_start_next(crtc_state);
 	else
-		return intel_vrr_vmax_vblank_start(crtc_state);
+		vblank_start = intel_vrr_dcb_vmax_vblank_start_next(crtc_state);
+
+	if (vblank_start >= 0)
+		return vblank_start;
+
+	if (is_push_sent)
+		vblank_start = intel_vrr_dcb_vmin_vblank_start_final(crtc_state);
+	else
+		vblank_start = intel_vrr_dcb_vmax_vblank_start_final(crtc_state);
+
+	return vblank_start;
 }
 
 void intel_vblank_evade_init(const struct intel_crtc_state *old_crtc_state,
-- 
2.48.1