3 files changed, 12 insertions, 5 deletions

diff --git a/drivers/gpu/drm/i915/i915_drv.c b/drivers/gpu/drm/i915/i915_drv.c
index 6ed73ae2133a..d988cc350f66 100644
--- a/drivers/gpu/drm/i915/i915_drv.c
+++ b/drivers/gpu/drm/i915/i915_drv.c
@@ -348,12 +348,17 @@ void gen6_gt_force_wake_put(struct drm_i915_private *dev_priv)
 
 void __gen6_gt_wait_for_fifo(struct drm_i915_private *dev_priv)
 {
-        int loop = 500;
-        u32 fifo = I915_READ_NOTRACE(GT_FIFO_FREE_ENTRIES);
-        while (fifo < 20 && loop--) {
-                udelay(10);
-                fifo = I915_READ_NOTRACE(GT_FIFO_FREE_ENTRIES);
+        if (dev_priv->gt_fifo_count < GT_FIFO_NUM_RESERVED_ENTRIES ) {
+                int loop = 500;
+                u32 fifo = I915_READ_NOTRACE(GT_FIFO_FREE_ENTRIES);
+                while (fifo <= GT_FIFO_NUM_RESERVED_ENTRIES && loop--) {
+                        udelay(10);
+                        fifo = I915_READ_NOTRACE(GT_FIFO_FREE_ENTRIES);
+                }
+                WARN_ON(loop < 0 && fifo <= GT_FIFO_NUM_RESERVED_ENTRIES);
+                dev_priv->gt_fifo_count = fifo;
         }
+        dev_priv->gt_fifo_count--;
 }
 
 static int i915_drm_freeze(struct drm_device *dev)
diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index 00dc59a51ccd..b37146c4526f 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -277,6 +277,7 @@ typedef struct drm_i915_private {
         int relative_constants_mode;
 
         void __iomem *regs;
+        u32 gt_fifo_count;
 
         struct intel_gmbus {
                 struct i2c_adapter adapter;
diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
index 96fb0fa47c40..02db299f621a 100644
--- a/drivers/gpu/drm/i915/i915_reg.h
+++ b/drivers/gpu/drm/i915/i915_reg.h
@@ -3361,6 +3361,7 @@
 #define  FORCEWAKE_ACK                          0x130090
 
 #define  GT_FIFO_FREE_ENTRIES                   0x120008
+#define    GT_FIFO_NUM_RESERVED_ENTRIES         20
 
 #define GEN6_RPNSWREQ                           0xA008
 #define   GEN6_TURBO_DISABLE                    (1<<31)