drm/i915/kbl: Add WaEnableGapsTsvCreditFix

We need this crucial workaround from skl also to all kbl revisions.
Lack of it was causing system hangs on skl enabling so this is
a must have.

v2: Don't add revid checks to gen9 init workarounds (Arun)

References: HSD#2126660
Cc: Arun Siluvery <arun.siluvery@linux.intel.com>
Signed-off-by: Mika Kuoppala <mika.kuoppala@intel.com>
Reviewed-by: Matthew Auld <matthew.auld@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1465309159-30531-8-git-send-email-mika.kuoppala@intel.com
(cherry picked from commit e587f6cb0af140f3c0ea794d8616eb9a29969983)
Signed-off-by: Mika Kuoppala <mika.kuoppala@intel.com>

diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.c b/drivers/gpu/drm/i915/intel_ringbuffer.c
index 5c7f3cff50ccd5877c33e87e471fed831ccfc968..6d844e2147b8226fec95e53c7137551badfbcc95 100644 (file)
--- a/drivers/gpu/drm/i915/intel_ringbuffer.c
+++ b/drivers/gpu/drm/i915/intel_ringbuffer.c
@@ -1191,12 +1191,17 @@ static int bxt_init_workarounds(struct intel_engine_cs *engine)
 
 static int kbl_init_workarounds(struct intel_engine_cs *engine)
 {
+       struct drm_i915_private *dev_priv = engine->dev->dev_private;
        int ret;
 
        ret = gen9_init_workarounds(engine);
        if (ret)
                return ret;
 
+       /* WaEnableGapsTsvCreditFix:kbl */
+       I915_WRITE(GEN8_GARBCNTL, (I915_READ(GEN8_GARBCNTL) |
+                                  GEN9_GAPS_TSV_CREDIT_DISABLE));
+
        return 0;
 }