drm/i915: Use old mbus_join value when increasing CDCLK

In order to make sure we are not breaking the proper sequence
let's do updates step by step and don't change MBUS join value
during MDCLK/CDCLK programming stage.
MBUS join programming would be taken care by pre/post ddb hooks.

v2: - Reworded comment about using old mbus_join value in
      intel_set_cdclk(Ville Syrjälä)

Reviewed-by: Uma Shankar <uma.shankar@intel.com>
Signed-off-by: Stanislav Lisovskiy <stanislav.lisovskiy@intel.com>
[v3: vsyrjala: rebase on top of cdclk changes, reword a bit more]
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240402155016.13733-11-ville.syrjala@linux.intel.com

diff --git a/drivers/gpu/drm/i915/display/intel_cdclk.c b/drivers/gpu/drm/i915/display/intel_cdclk.c
index ed8d9ee094b8542ff0b0341cb331d7f52bd9d4c3..e0c69d85e7338ed6dd2f9bb2e4e56f73b2c14250 100644 (file)
--- a/drivers/gpu/drm/i915/display/intel_cdclk.c
+++ b/drivers/gpu/drm/i915/display/intel_cdclk.c
@@ -2617,6 +2617,12 @@ intel_set_cdclk_pre_plane_update(struct intel_atomic_state *state)
                                                 old_cdclk_state->actual.voltage_level);
        }
 
+       /*
+        * mbus joining will be changed later by
+        * intel_dbuf_mbus_{pre,post}_ddb_update()
+        */
+       cdclk_config.joined_mbus = old_cdclk_state->actual.joined_mbus;
+
        drm_WARN_ON(&i915->drm, !new_cdclk_state->base.changed);
 
        intel_set_cdclk(i915, &cdclk_config, pipe,