drm/radeon: fall back to GTT if bo creation/validation in VRAM fails.

This fixes a problem where on low VRAM cards we'd run out of space for validation.

[airlied: Tested on my M7, Thinkpad T42, compiz works with no problems.]
Signed-off-by: Michel Dänzer <daenzer@vmware.com>
Cc: stable@kernel.org
Signed-off-by: Dave Airlie <airlied@redhat.com>

drivers/gpu/drm/radeon/radeon_object.c

@@ -110,6 +110,7 @@ int radeon_bo_create(struct radeon_device *rdev, struct drm_gem_object *gobj,
 	bo->surface_reg = -1;
 	INIT_LIST_HEAD(&bo->list);
 
+retry:
 	radeon_ttm_placement_from_domain(bo, domain);
 	/* Kernel allocation are uninterruptible */
 	mutex_lock(&rdev->vram_mutex);
@@ -118,10 +119,15 @@ int radeon_bo_create(struct radeon_device *rdev, struct drm_gem_object *gobj,
 			&radeon_ttm_bo_destroy);
 	mutex_unlock(&rdev->vram_mutex);
 	if (unlikely(r != 0)) {
-		if (r != -ERESTARTSYS)
+		if (r != -ERESTARTSYS) {
+			if (domain == RADEON_GEM_DOMAIN_VRAM) {
+				domain |= RADEON_GEM_DOMAIN_GTT;
+				goto retry;
+			}
 			dev_err(rdev->dev,
 				"object_init failed for (%lu, 0x%08X)\n",
 				size, domain);
+		}
 		return r;
 	}
 	*bo_ptr = bo;
@@ -321,6 +327,7 @@ int radeon_bo_list_validate(struct list_head *head)
 {
 	struct radeon_bo_list *lobj;
 	struct radeon_bo *bo;
+	u32 domain;
 	int r;
 
 	list_for_each_entry(lobj, head, list) {
@@ -333,18 +340,20 @@ int radeon_bo_list_validate(struct list_head *head)
 	list_for_each_entry(lobj, head, list) {
 		bo = lobj->bo;
 		if (!bo->pin_count) {
-			if (lobj->wdomain) {
-				radeon_ttm_placement_from_domain(bo,
-								lobj->wdomain);
-			} else {
-				radeon_ttm_placement_from_domain(bo,
-								lobj->rdomain);
-			}
+			domain = lobj->wdomain ? lobj->wdomain : lobj->rdomain;
+			
+		retry:
+			radeon_ttm_placement_from_domain(bo, domain);
 			r = ttm_bo_validate(&bo->tbo, &bo->placement,
 						true, false, false);
-			if (unlikely(r))
+			if (unlikely(r)) {
+				if (r != -ERESTARTSYS && domain == RADEON_GEM_DOMAIN_VRAM) {
+					domain |= RADEON_GEM_DOMAIN_GTT;
+					goto retry;
+				}
 				return r;
 			}
+		}
 		lobj->gpu_offset = radeon_bo_gpu_offset(bo);
 		lobj->tiling_flags = bo->tiling_flags;
 	}