diff --git a/drivers/gpu/drm/i915/i915_dma.c b/drivers/gpu/drm/i915/i915_dma.c index a9533c54c93c766a73acc453d38377a9e0ef5a64..a9ae374861e788fe7ced3b6cf8f1f129c6e84c86 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; } diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h index 8ba88cfc36dedc60bcd31e9a89a8f0023733aec1..39a72f642b3324f21051695ff5b70a296897e301 100644 --- a/drivers/gpu/drm/i915/i915_drv.h +++ b/drivers/gpu/drm/i915/i915_drv.h @@ -713,6 +713,7 @@ typedef struct drm_i915_private { u64 last_count1; unsigned long last_time1; + unsigned long chipset_power; u64 last_count2; struct timespec last_time2; unsigned long gfx_power;