drm/radeon: prevent crash in the ring space allocation

[pandora-kernel.git] / drivers / gpu / drm / radeon / radeon_ring.c

diff --git a/drivers/gpu/drm/radeon/radeon_ring.c b/drivers/gpu/drm/radeon/radeon_ring.c
index 49d5820..65be5e8 100644 (file)
--- a/drivers/gpu/drm/radeon/radeon_ring.c
+++ b/drivers/gpu/drm/radeon/radeon_ring.c
@@ -306,6 +306,9 @@ int radeon_ring_alloc(struct radeon_device *rdev, unsigned ndw)
 {
        int r;
 
+       /* make sure we aren't trying to allocate more space than there is on the ring */
+       if (ndw > (rdev->cp.ring_size / 4))
+               return -ENOMEM;
        /* Align requested size with padding so unlock_commit can
         * pad safely */
        ndw = (ndw + rdev->cp.align_mask) & ~rdev->cp.align_mask;