drm/i915:gen9: restrict WaC6DisallowByGfxPause

WaC6DisallowByGfxPause is currently applied unconditionally
but is not required in all revisions.

v2: extend application of workaround to agree with w/a
database, which differs from the HSD.

References: HSD#2133391
Signed-off-by: Tim Gore <tim.gore@intel.com>
Reviewed-by: Sagar Arun Kamble <sagar.a.kamble@intel.com>
Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1469008825-19442-1-git-send-email-tim.gore@intel.com

diff --git a/drivers/gpu/drm/i915/intel_guc_loader.c b/drivers/gpu/drm/i915/intel_guc_loader.c
index a6a8fba..b883efd 100644 (file)
--- a/drivers/gpu/drm/i915/intel_guc_loader.c
+++ b/drivers/gpu/drm/i915/intel_guc_loader.c
@@ -349,7 +349,9 @@ static int guc_ucode_xfer(struct drm_i915_private *dev_priv)
        }
 
        /* WaC6DisallowByGfxPause*/
-       I915_WRITE(GEN6_GFXPAUSE, 0x30FFF);
+       if (IS_SKL_REVID(dev, 0, SKL_REVID_C0) ||
+           IS_BXT_REVID(dev, 0, BXT_REVID_B0))
+               I915_WRITE(GEN6_GFXPAUSE, 0x30FFF);
 
        if (IS_BROXTON(dev))
                I915_WRITE(GEN9LP_GT_PM_CONFIG, GT_DOORBELL_ENABLE);