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authorMatthew Auld <matthew.auld@intel.com>2019-08-09 20:34:55 +0100
committerChris Wilson <chris@chris-wilson.co.uk>2019-08-10 13:18:32 +0100
commit1feb7864b2cbd874a677ce04d61834d5664133ab (patch)
tree8bc62abd733909cab90a4766ea3e2f2b3f724a2a
parent18851edfa7dbe156cfc5a73bf009d8a4def84bb5 (diff)
drm/i915/gtt: enable GTT cache by default
For some platforms the GTT cache is by default not enabled, and currently where we explicitly enable it, we make it conditional on 2M GTT page support, since the BSpec states that we must disable it if we enable 2M/1G pages. To make this more consistent opt for blanket enabling the GTT cache for all relevant gens in a single place, while still keeping the same behaviour of checking for 2M support. BSpec: 9314 BSpec: 423 Signed-off-by: Matthew Auld <matthew.auld@intel.com> Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com> Cc: Chris Wilson <chris@chris-wilson.co.uk> 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/20190809193456.3836-1-matthew.auld@intel.com
-rw-r--r--drivers/gpu/drm/i915/i915_gem_gtt.c21
-rw-r--r--drivers/gpu/drm/i915/intel_pm.c12
2 files changed, 21 insertions, 12 deletions
diff --git a/drivers/gpu/drm/i915/i915_gem_gtt.c b/drivers/gpu/drm/i915/i915_gem_gtt.c
index 83a02e773c58..72a227c43e35 100644
--- a/drivers/gpu/drm/i915/i915_gem_gtt.c
+++ b/drivers/gpu/drm/i915/i915_gem_gtt.c
@@ -2035,6 +2035,27 @@ static void gtt_write_workarounds(struct intel_gt *gt)
GEN8_GAMW_ECO_DEV_RW_IA,
0,
GAMW_ECO_ENABLE_64K_IPS_FIELD);
+
+ if (IS_GEN_RANGE(i915, 8, 11)) {
+ bool can_use_gtt_cache = true;
+
+ /*
+ * According to the BSpec if we use 2M/1G pages then we also
+ * need to disable the GTT cache. At least on BDW we can see
+ * visual corruption when using 2M pages, and not disabling the
+ * GTT cache.
+ */
+ if (HAS_PAGE_SIZES(i915, I915_GTT_PAGE_SIZE_2M))
+ can_use_gtt_cache = false;
+
+ /* WaGttCachingOffByDefault */
+ intel_uncore_write(uncore,
+ HSW_GTT_CACHE_EN,
+ can_use_gtt_cache ? GTT_CACHE_EN_ALL : 0);
+ WARN_ON_ONCE(can_use_gtt_cache &&
+ intel_uncore_read(uncore,
+ HSW_GTT_CACHE_EN) == 0);
+ }
}
int i915_ppgtt_init_hw(struct intel_gt *gt)
diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c
index 780df8db2eba..aca676e79948 100644
--- a/drivers/gpu/drm/i915/intel_pm.c
+++ b/drivers/gpu/drm/i915/intel_pm.c
@@ -9169,9 +9169,6 @@ static void skl_init_clock_gating(struct drm_i915_private *dev_priv)
static void bdw_init_clock_gating(struct drm_i915_private *dev_priv)
{
- /* The GTT cache must be disabled if the system is using 2M pages. */
- bool can_use_gtt_cache = !HAS_PAGE_SIZES(dev_priv,
- I915_GTT_PAGE_SIZE_2M);
enum pipe pipe;
/* WaSwitchSolVfFArbitrationPriority:bdw */
@@ -9204,9 +9201,6 @@ static void bdw_init_clock_gating(struct drm_i915_private *dev_priv)
/* WaProgramL3SqcReg1Default:bdw */
gen8_set_l3sqc_credits(dev_priv, 30, 2);
- /* WaGttCachingOffByDefault:bdw */
- I915_WRITE(HSW_GTT_CACHE_EN, can_use_gtt_cache ? GTT_CACHE_EN_ALL : 0);
-
/* WaKVMNotificationOnConfigChange:bdw */
I915_WRITE(CHICKEN_PAR2_1, I915_READ(CHICKEN_PAR2_1)
| KVM_CONFIG_CHANGE_NOTIFICATION_SELECT);
@@ -9471,12 +9465,6 @@ static void chv_init_clock_gating(struct drm_i915_private *dev_priv)
* LSQC Setting Recommendations.
*/
gen8_set_l3sqc_credits(dev_priv, 38, 2);
-
- /*
- * GTT cache may not work with big pages, so if those
- * are ever enabled GTT cache may need to be disabled.
- */
- I915_WRITE(HSW_GTT_CACHE_EN, GTT_CACHE_EN_ALL);
}
static void g4x_init_clock_gating(struct drm_i915_private *dev_priv)