[PATCH 1/5] drm/i915: Update mbus in intel_dbuf_mbus_update and do it properly

[Stanislav Lisovskiy]

According to BSpec we need to do correspondent MBUS updates before
or after DBUF reallocation, depending on whether we are enabling
or disabling mbus joining(typical scenario is swithing between
multiple and single displays).

Signed-off-by: Stanislav Lisovskiy <stanislav.lisovskiy at intel.com>
---
 drivers/gpu/drm/i915/display/skl_watermark.c | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/i915/display/skl_watermark.c b/drivers/gpu/drm/i915/display/skl_watermark.c
index bc341abcab2fe..8ff69da664807 100644
--- a/drivers/gpu/drm/i915/display/skl_watermark.c
+++ b/drivers/gpu/drm/i915/display/skl_watermark.c
@@ -3574,7 +3574,7 @@ void intel_dbuf_mdclk_cdclk_ratio_update(struct drm_i915_private *i915, u8 ratio
  * Configure MBUS_CTL and all DBUF_CTL_S of each slice to join_mbus state before
  * update the request state of all DBUS slices.
  */
-static void update_mbus_pre_enable(struct intel_atomic_state *state)
+static void intel_dbuf_mbus_update(struct intel_atomic_state *state)
 {
 	struct drm_i915_private *i915 = to_i915(state->base.dev);
 	u32 mbus_ctl;
@@ -3632,7 +3632,9 @@ void intel_dbuf_pre_plane_update(struct intel_atomic_state *state)
 
 	WARN_ON(!new_dbuf_state->base.changed);
 
-	update_mbus_pre_enable(state);
+	if (!old_dbuf_state->joined_mbus && new_dbuf_state->joined_mbus)
+		intel_dbuf_mbus_update(state);
+
 	gen9_dbuf_slices_update(i915,
 				old_dbuf_state->enabled_slices |
 				new_dbuf_state->enabled_slices);
@@ -3653,6 +3655,9 @@ void intel_dbuf_post_plane_update(struct intel_atomic_state *state)
 
 	WARN_ON(!new_dbuf_state->base.changed);
 
+	if (old_dbuf_state->joined_mbus && !new_dbuf_state->joined_mbus)
+		intel_dbuf_mbus_update(state);
+
 	gen9_dbuf_slices_update(i915,
 				new_dbuf_state->enabled_slices);
 }
-- 
2.37.3