drm/i915/tgl: Implement Wa_1409804808

This workaround the CS not done issue on PIPE_CONTROL.

v2:
- replaced BIT() by REG_BIT() in all GEN7_ROW_CHICKEN2() bits
- shortened the name of the new bit

BSpec: 52890
BSpec: 46218
Cc: Matt Roper <matthew.d.roper@intel.com>
Reviewed-by: Matt Roper <matthew.d.roper@intel.com>
Signed-off-by: José Roberto de Souza <jose.souza@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200227220101.321671-1-jose.souza@intel.com

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

@@ -1362,6 +1362,12 @@ rcs_engine_wa_init(struct intel_engine_cs *engine, struct i915_wa_list *wal)
 			     GEN12_DISABLE_EARLY_READ);
 	}
 
+	if (IS_TIGERLAKE(i915)) {
+		/* Wa_1409804808:tgl */
+		wa_masked_en(wal, GEN7_ROW_CHICKEN2,
+			     GEN12_PUSH_CONST_DEREF_HOLD_DIS);
+	}
+
 	if (IS_GEN(i915, 11)) {
 		/* This is not an Wa. Enable for better image quality */
 		wa_masked_en(wal,

drivers/gpu/drm/i915/i915_reg.h

@@ -9141,7 +9141,8 @@ enum {
 #define   DISABLE_EARLY_EOT			(1 << 1)
 
 #define GEN7_ROW_CHICKEN2			_MMIO(0xe4f4)
-#define GEN12_DISABLE_EARLY_READ	BIT(14)
+#define   GEN12_DISABLE_EARLY_READ		REG_BIT(14)
+#define   GEN12_PUSH_CONST_DEREF_HOLD_DIS	REG_BIT(8)
 
 #define GEN7_ROW_CHICKEN2_GT2		_MMIO(0xf4f4)
 #define   DOP_CLOCK_GATING_DISABLE	(1 << 0)