drm/i915/tgl: Wa_1606679103

Extend disabling SAMPLER_STATE prefetch workaround to gen12.

v2: Limit the WA to TGL A0 and update the WA no(Chris)

BSpec: 52890
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Signed-off-by: Radhakrishna Sripada <radhakrishna.sripada@intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20191113231953.24853-1-radhakrishna.sripada@intel.com

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

@@ -1315,6 +1315,14 @@ rcs_engine_wa_init(struct intel_engine_cs *engine, struct i915_wa_list *wal)
 			     GEN6_RC_SLEEP_PSMI_CONTROL,
 			     GEN12_WAIT_FOR_EVENT_POWER_DOWN_DISABLE |
 			     GEN8_RC_SEMA_IDLE_MSG_DISABLE);
+
+		/*
+		 * Wa_1606679103:tgl
+		 * (see also Wa_1606682166:icl)
+		 */
+		wa_write_or(wal,
+			    GEN7_SARCHKMD,
+			    GEN7_DISABLE_SAMPLER_PREFETCH);
 	}
 
 	if (IS_GEN(i915, 11)) {