diff --git a/drivers/gpu/drm/i915/i915_dma.c b/drivers/gpu/drm/i915/i915_dma.c index 051134c56aef5d52b4aa8813ffd850b1d3b33a1f..3133f991968d1c66384502aa30c163b1e822ef37 100644 --- a/drivers/gpu/drm/i915/i915_dma.c +++ b/drivers/gpu/drm/i915/i915_dma.c @@ -1011,8 +1011,16 @@ static int i915_load_modeset_init(struct drm_device *dev) /* Basic memrange allocator for stolen space (aka vram) */ drm_mm_init(&dev_priv->vram, 0, prealloc_size); - /* Let GEM Manage from end of prealloc space to end of aperture */ - i915_gem_do_init(dev, prealloc_size, agp_size); + /* Let GEM Manage from end of prealloc space to end of aperture. + * + * However, leave one page at the end still bound to the scratch page. + * There are a number of places where the hardware apparently + * prefetches past the end of the object, and we've seen multiple + * hangs with the GPU head pointer stuck in a batchbuffer bound + * at the last page of the aperture. One page should be enough to + * keep any prefetching inside of the aperture. + */ + i915_gem_do_init(dev, prealloc_size, agp_size - 4096); ret = i915_gem_init_ringbuffer(dev); if (ret)