From 2cbecff4122cedff329e3efa32c7f2266125c4a1 Mon Sep 17 00:00:00 2001
From: Oscar Mateo <oscar.mateo@intel.com>
Date: Wed, 23 Aug 2017 12:56:31 -0700
Subject: [PATCH] drm/i915/cnl: WaPushConstantDereferenceHoldDisable
Git-commit: 2cbecff4122cedff329e3efa32c7f2266125c4a1
Patch-mainline: v4.15-rc1
References: FATE#322643 bsc#1055900
CS sometimes hangs on 3D Push Constant dispatches with the new
deref enhancement logic in CNL.
V2: Improve the commit message (Rodrigo)
Cc: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Signed-off-by: Oscar Mateo <oscar.mateo@intel.com>
Reviewed-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/1503518191-19116-1-git-send-email-oscar.mateo@intel.com
Acked-by: Takashi Iwai <tiwai@suse.de>
---
drivers/gpu/drm/i915/i915_reg.h | 1 +
drivers/gpu/drm/i915/intel_engine_cs.c | 3 +++
2 files changed, 4 insertions(+)
--- a/drivers/gpu/drm/i915/i915_reg.h
+++ b/drivers/gpu/drm/i915/i915_reg.h
@@ -8056,6 +8056,7 @@ enum {
#define GEN7_ROW_CHICKEN2 _MMIO(0xe4f4)
#define GEN7_ROW_CHICKEN2_GT2 _MMIO(0xf4f4)
#define DOP_CLOCK_GATING_DISABLE (1<<0)
+#define PUSH_CONSTANT_DEREF_DISABLE (1<<8)
#define HSW_ROW_CHICKEN3 _MMIO(0xe49c)
#define HSW_ROW_CHICKEN3_L3_GLOBAL_ATOMICS_DISABLE (1 << 6)
--- a/drivers/gpu/drm/i915/intel_engine_cs.c
+++ b/drivers/gpu/drm/i915/intel_engine_cs.c
@@ -1086,6 +1086,9 @@ static int cnl_init_workarounds(struct i
WA_SET_BIT(GEN9_GAMT_ECO_REG_RW_IA,
GAMT_ECO_ENABLE_IN_PLACE_DECOMPRESS);
+ /* WaPushConstantDereferenceHoldDisable:cnl */
+ WA_SET_BIT(GEN7_ROW_CHICKEN2, PUSH_CONSTANT_DEREF_DISABLE);
+
/* WaEnablePreemptionGranularityControlByUMD:cnl */
ret= wa_ring_whitelist_reg(engine, GEN8_CS_CHICKEN1);
if (ret)