[Intel-gfx] [PATCH v2] drm/i915: Remove i915 ggtt WA since GT E0

[dong.yang at intel.com]

From: "Yang, Dong" <dong.yang at intel.com>

Broxton steppings starting from GT E0 have fixed the bug, remove
WA since stepping GT E0.

v2: add comment in code, by:
Joonas Lahtinen <joonas.lahtinen at linux.intel.com>

Signed-off-by: Yang, Dong <dong.yang at intel.com>
---
 drivers/gpu/drm/i915/i915_drv.h | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index 5f3e5c13fbaa..a0dfd1926b1b 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -2141,6 +2141,8 @@ IS_SUBPLATFORM(const struct drm_i915_private *i915,
 #define BXT_REVID_B0		0x3
 #define BXT_REVID_B_LAST	0x8
 #define BXT_REVID_C0		0x9
+#define BXT_REVID_D0		0xC
+#define BXT_REVID_E0		0xD
 
 #define IS_BXT_REVID(dev_priv, since, until) \
 	(IS_BROXTON(dev_priv) && IS_REVID(dev_priv, since, until))
@@ -2357,7 +2359,8 @@ static inline bool intel_scanout_needs_vtd_wa(struct drm_i915_private *dev_priv)
 static inline bool
 intel_ggtt_update_needs_vtd_wa(struct drm_i915_private *dev_priv)
 {
-	return IS_BROXTON(dev_priv) && intel_vtd_active();
+	/* Broxton steppings starting from E0 have fixed the bug. */
+	return IS_BXT_REVID(dev_priv, 0, BXT_REVID_D0) && intel_vtd_active();
 }
 
 /* i915_drv.c */
-- 
2.22.0