[Intel-gfx] [PATCH] drm/i915: Write zero wms if we disable planes for icl+

[Stanislav Lisovskiy]

Otherwise we seem to get FIFO underruns. It is being disabled
anyway, so kind of logical to write those as zeroes, even if
disabling is temporary.

Signed-off-by: Stanislav Lisovskiy <stanislav.lisovskiy at intel.com>
---
 .../drm/i915/display/skl_universal_plane.c    |  2 +-
 drivers/gpu/drm/i915/intel_pm.c               | 46 +++++++++++++++++++
 drivers/gpu/drm/i915/intel_pm.h               |  2 +
 3 files changed, 49 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/i915/display/skl_universal_plane.c b/drivers/gpu/drm/i915/display/skl_universal_plane.c
index caa03324a733..c0251189c042 100644
--- a/drivers/gpu/drm/i915/display/skl_universal_plane.c
+++ b/drivers/gpu/drm/i915/display/skl_universal_plane.c
@@ -633,7 +633,7 @@ icl_plane_disable_arm(struct intel_plane *plane,
 	if (icl_is_hdr_plane(dev_priv, plane_id))
 		intel_de_write_fw(dev_priv, PLANE_CUS_CTL(pipe, plane_id), 0);
 
-	skl_write_plane_wm(plane, crtc_state);
+	skl_write_zero_plane_wm(plane, crtc_state);
 
 	intel_psr2_disable_plane_sel_fetch(plane, crtc_state);
 	intel_de_write_fw(dev_priv, PLANE_CTL(pipe, plane_id), 0);
diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c
index ee0047fdc95d..2470c037bfae 100644
--- a/drivers/gpu/drm/i915/intel_pm.c
+++ b/drivers/gpu/drm/i915/intel_pm.c
@@ -5885,6 +5885,52 @@ void skl_write_plane_wm(struct intel_plane *plane,
 				    PLANE_NV12_BUF_CFG(pipe, plane_id), ddb_y);
 }
 
+void skl_write_zero_plane_wm(struct intel_plane *plane,
+			     const struct intel_crtc_state *crtc_state)
+{
+	struct drm_i915_private *dev_priv = to_i915(plane->base.dev);
+	int level, max_level = ilk_wm_max_level(dev_priv);
+	enum plane_id plane_id = plane->id;
+	enum pipe pipe = plane->pipe;
+	struct skl_pipe_wm pipe_wm;
+	const struct skl_ddb_entry *ddb =
+		&crtc_state->wm.skl.plane_ddb[plane_id];
+	const struct skl_ddb_entry *ddb_y =
+		&crtc_state->wm.skl.plane_ddb_y[plane_id];
+
+	for (level = 0; level <= max_level; level++) {
+		pipe_wm.planes[plane_id].wm[level].blocks = 0;
+		pipe_wm.planes[plane_id].wm[level].lines = 0;
+	}
+
+	pipe_wm.planes[plane_id].trans_wm.blocks = 0;
+	pipe_wm.planes[plane_id].trans_wm.lines = 0;
+
+	for (level = 0; level <= max_level; level++)
+		skl_write_wm_level(dev_priv, PLANE_WM(pipe, plane_id, level),
+				   skl_plane_wm_level(&pipe_wm, plane_id, level));
+
+	skl_write_wm_level(dev_priv, PLANE_WM_TRANS(pipe, plane_id),
+			   skl_plane_trans_wm(&pipe_wm, plane_id));
+
+	if (HAS_HW_SAGV_WM(dev_priv)) {
+		const struct skl_plane_wm *wm = &pipe_wm.planes[plane_id];
+
+		skl_write_wm_level(dev_priv, PLANE_WM_SAGV(pipe, plane_id),
+				   &wm->sagv.wm0);
+		skl_write_wm_level(dev_priv, PLANE_WM_SAGV_TRANS(pipe, plane_id),
+				   &wm->sagv.trans_wm);
+	}
+
+	skl_ddb_entry_write(dev_priv,
+			    PLANE_BUF_CFG(pipe, plane_id), ddb);
+
+	if (DISPLAY_VER(dev_priv) < 11)
+		skl_ddb_entry_write(dev_priv,
+				    PLANE_NV12_BUF_CFG(pipe, plane_id), ddb_y);
+}
+
+
 void skl_write_cursor_wm(struct intel_plane *plane,
 			 const struct intel_crtc_state *crtc_state)
 {
diff --git a/drivers/gpu/drm/i915/intel_pm.h b/drivers/gpu/drm/i915/intel_pm.h
index 50604cf7398c..fb0ac4f143ab 100644
--- a/drivers/gpu/drm/i915/intel_pm.h
+++ b/drivers/gpu/drm/i915/intel_pm.h
@@ -61,6 +61,8 @@ bool skl_wm_level_equals(const struct skl_wm_level *l1,
 bool skl_ddb_allocation_overlaps(const struct skl_ddb_entry *ddb,
 				 const struct skl_ddb_entry *entries,
 				 int num_entries, int ignore_idx);
+void skl_write_zero_plane_wm(struct intel_plane *plane,
+			     const struct intel_crtc_state *crtc_state);
 void skl_write_plane_wm(struct intel_plane *plane,
 			const struct intel_crtc_state *crtc_state);
 void skl_write_cursor_wm(struct intel_plane *plane,
-- 
2.24.1.485.gad05a3d8e5