drm/i915/xelpmp: Add Wa_16021867713

This workaround applies to all steppings of Xe_LPM+. Implement the KMD
part.

v2:
    - Put the definition of VDBOX_CGCTL3F1C() in the correct sort order.
      (Matt)
Reviewed-by: Matt Roper <matthew.d.roper@intel.com>
Signed-off-by: Gustavo Sousa <gustavo.sousa@intel.com>
Signed-off-by: Matt Roper <matthew.d.roper@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20231106201959.156943-1-gustavo.sousa@intel.com

drivers/gpu/drm/i915/gt/intel_engine_regs.h

@@ -263,5 +263,7 @@
 #define VDBOX_CGCTL3F18(base)			_MMIO((base) + 0x3f18)
 #define   ALNUNIT_CLKGATE_DIS			REG_BIT(13)
 
+#define VDBOX_CGCTL3F1C(base)			_MMIO((base) + 0x3f1c)
+#define   MFXPIPE_CLKGATE_DIS			REG_BIT(3)
 
 #endif /* __INTEL_ENGINE_REGS__ */

drivers/gpu/drm/i915/gt/intel_workarounds.c

@@ -1662,9 +1662,23 @@ xelpg_gt_workarounds_init(struct intel_gt *gt, struct i915_wa_list *wal)
 	debug_dump_steering(gt);
 }
 
+static void
+wa_16021867713(struct intel_gt *gt, struct i915_wa_list *wal)
+{
+	struct intel_engine_cs *engine;
+	int id;
+
+	for_each_engine(engine, gt, id)
+		if (engine->class == VIDEO_DECODE_CLASS)
+			wa_write_or(wal, VDBOX_CGCTL3F1C(engine->mmio_base),
+				    MFXPIPE_CLKGATE_DIS);
+}
+
 static void
 xelpmp_gt_workarounds_init(struct intel_gt *gt, struct i915_wa_list *wal)
 {
+	wa_16021867713(gt, wal);
+
 	/*
 	 * Wa_14018778641
 	 * Wa_18018781329