[PATCH 5/6] drm/i915: Sanitize MBUS joining

[Ville Syrjala <ville.syrjala@linux.intel.com>]

From: Ville Syrjälä <ville.syrjala@linux.intel.com>

If the system boots with MBUS joining enabled but we disable
the relevant pipe during sanitaion we later get into trouble
as the rest of the code doesn't expect MBUS joining to be
enabled unless the set of active pipes is in agreement.

We could relax some of the MBUS joining related checks during
normal atomic commits to let this slide, but that might also
let some real bugs through. So let's sanitize the MBUS joining
instead. And in order to keep things more or less in sync we'll
do the related credit, cdclk/mdclk ratio, etc. updates as well.

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
---
 drivers/gpu/drm/i915/display/skl_watermark.c | 29 ++++++++++++++++++--
 1 file changed, 27 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/i915/display/skl_watermark.c b/drivers/gpu/drm/i915/display/skl_watermark.c
index 2eefeff6693a..98f9e01b2a1c 100644
--- a/drivers/gpu/drm/i915/display/skl_watermark.c
+++ b/drivers/gpu/drm/i915/display/skl_watermark.c
@@ -3567,6 +3567,29 @@ void intel_dbuf_post_plane_update(struct intel_atomic_state *state)
 	gen9_dbuf_slices_update(i915, new_slices);
 }
 
+static void skl_mbus_sanitize(struct drm_i915_private *i915)
+{
+	struct intel_dbuf_state *dbuf_state =
+		to_intel_dbuf_state(i915->display.dbuf.obj.state);
+
+	if (!HAS_MBUS_JOINING(i915))
+		return;
+
+	if (!dbuf_state->joined_mbus ||
+	    adlp_check_mbus_joined(dbuf_state->active_pipes))
+		return;
+
+	drm_dbg_kms(&i915->drm, "Disabling redundant MBUS joining (active pipes 0x%x)\n",
+		    dbuf_state->active_pipes);
+
+	dbuf_state->joined_mbus = false;
+	intel_dbuf_mdclk_cdclk_ratio_update(i915,
+					    dbuf_state->mdclk_cdclk_ratio,
+					    dbuf_state->joined_mbus);
+	pipe_mbus_dbox_ctl_update(i915, dbuf_state);
+	mbus_ctl_join_update(i915, dbuf_state, INVALID_PIPE);
+}
+
 static bool skl_dbuf_is_misconfigured(struct drm_i915_private *i915)
 {
 	const struct intel_dbuf_state *dbuf_state =
@@ -3599,7 +3622,7 @@ static bool skl_dbuf_is_misconfigured(struct drm_i915_private *i915)
 	return false;
 }
 
-static void skl_wm_sanitize(struct drm_i915_private *i915)
+static void skl_dbuf_sanitize(struct drm_i915_private *i915)
 {
 	struct intel_crtc *crtc;
 
@@ -3638,7 +3661,9 @@ static void skl_wm_sanitize(struct drm_i915_private *i915)
 static void skl_wm_get_hw_state_and_sanitize(struct drm_i915_private *i915)
 {
 	skl_wm_get_hw_state(i915);
-	skl_wm_sanitize(i915);
+
+	skl_mbus_sanitize(i915);
+	skl_dbuf_sanitize(i915);
 }
 
 void intel_wm_state_verify(struct intel_atomic_state *state,
-- 
2.45.2