drm/i915/dmc: Don't enable any pipe DMC events

The pipe DMC may be making a mess of things. Keep all event handlers
disabled until needed (which is never atm). This is also what Windows
does on adl+.

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>

Author: vsyrjala

drivers/gpu/drm/i915/display/intel_dmc.c

@@ -493,6 +493,31 @@ void intel_dmc_disable_pipe(struct drm_i915_private *i915, enum pipe pipe)
 		intel_de_rmw(i915, PIPEDMC_CONTROL(pipe), PIPEDMC_ENABLE, 0);
 }
 
+static bool is_dmc_evt_reg(struct drm_i915_private *i915,
+			   enum intel_dmc_id dmc_id, i915_reg_t reg)
+{
+	u32 offset = i915_mmio_reg_offset(reg);
+	u32 start = i915_mmio_reg_offset(DMC_EVT_CTL(i915, dmc_id, 0));
+	u32 end = i915_mmio_reg_offset(DMC_EVT_CTL(i915, dmc_id, DMC_EVENT_HANDLER_COUNT_GEN12));
+
+	return offset >= start && offset < end;
+}
+
+static u32 dmc_mmiodata(struct drm_i915_private *i915,
+			struct intel_dmc *dmc,
+			enum intel_dmc_id dmc_id, int i)
+{
+	/* keep all pipe DMC events disabled by default */
+	if (dmc_id != DMC_FW_MAIN &&
+	    is_dmc_evt_reg(i915, dmc_id, dmc->dmc_info[dmc_id].mmioaddr[i]))
+		return REG_FIELD_PREP(DMC_EVT_CTL_TYPE_MASK,
+				      DMC_EVT_CTL_TYPE_EDGE_0_1) |
+			REG_FIELD_PREP(DMC_EVT_CTL_EVENT_ID_MASK,
+				       DMC_EVT_CTL_EVENT_ID_FALSE);
+	else
+		return dmc->dmc_info[dmc_id].mmiodata[i];
+}
+
 /**
  * intel_dmc_load_program() - write the firmware from memory to register.
  * @i915: i915 drm device.
@@ -532,7 +557,7 @@ void intel_dmc_load_program(struct drm_i915_private *i915)
 	for_each_dmc_id(dmc_id) {
 		for (i = 0; i < dmc->dmc_info[dmc_id].mmio_count; i++) {
 			intel_de_write(i915, dmc->dmc_info[dmc_id].mmioaddr[i],
-				       dmc->dmc_info[dmc_id].mmiodata[i]);
+				       dmc_mmiodata(i915, dmc, dmc_id, i));
 		}
 	}