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path: root/drivers/gpu/drm/i915/i915_dma.c
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Diffstat (limited to 'drivers/gpu/drm/i915/i915_dma.c')
-rw-r--r--drivers/gpu/drm/i915/i915_dma.c10
1 files changed, 10 insertions, 0 deletions
diff --git a/drivers/gpu/drm/i915/i915_dma.c b/drivers/gpu/drm/i915/i915_dma.c
index a9533c54c93c..a9ae374861e7 100644
--- a/drivers/gpu/drm/i915/i915_dma.c
+++ b/drivers/gpu/drm/i915/i915_dma.c
@@ -1454,6 +1454,14 @@ unsigned long i915_chipset_val(struct drm_i915_private *dev_priv)
diff1 = now - dev_priv->last_time1;
+ /* Prevent division-by-zero if we are asking too fast.
+ * Also, we don't get interesting results if we are polling
+ * faster than once in 10ms, so just return the saved value
+ * in such cases.
+ */
+ if (diff1 <= 10)
+ return dev_priv->chipset_power;
+
count1 = I915_READ(DMIEC);
count2 = I915_READ(DDREC);
count3 = I915_READ(CSIEC);
@@ -1484,6 +1492,8 @@ unsigned long i915_chipset_val(struct drm_i915_private *dev_priv)
dev_priv->last_count1 = total_count;
dev_priv->last_time1 = now;
+ dev_priv->chipset_power = ret;
+
return ret;
}