1 files changed, 22 insertions, 4 deletions

diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index 3b6eb651d88a..c6f80bc3b7bc 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -2342,7 +2342,8 @@ static struct sg_table *
 i915_gem_object_get_pages_gtt(struct drm_i915_gem_object *obj)
 {
         struct drm_i915_private *dev_priv = to_i915(obj->base.dev);
-        int page_count, i;
+        const unsigned long page_count = obj->base.size / PAGE_SIZE;
+        unsigned long i;
         struct address_space *mapping;
         struct sg_table *st;
         struct scatterlist *sg;
@@ -2368,7 +2369,7 @@ i915_gem_object_get_pages_gtt(struct drm_i915_gem_object *obj)
         if (st == NULL)
                 return ERR_PTR(-ENOMEM);
 
-        page_count = obj->base.size / PAGE_SIZE;
+rebuild_st:
         if (sg_alloc_table(st, page_count, GFP_KERNEL)) {
                 kfree(st);
                 return ERR_PTR(-ENOMEM);
@@ -2427,8 +2428,25 @@ i915_gem_object_get_pages_gtt(struct drm_i915_gem_object *obj)
         i915_sg_trim(st);
 
         ret = i915_gem_gtt_prepare_pages(obj, st);
-        if (ret)
-                goto err_pages;
+        if (ret) {
+                /* DMA remapping failed? One possible cause is that
+                 * it could not reserve enough large entries, asking
+                 * for PAGE_SIZE chunks instead may be helpful.
+                 */
+                if (max_segment > PAGE_SIZE) {
+                        for_each_sgt_page(page, sgt_iter, st)
+                                put_page(page);
+                        sg_free_table(st);
+
+                        max_segment = PAGE_SIZE;
+                        goto rebuild_st;
+                } else {
+                        dev_warn(&dev_priv->drm.pdev->dev,
+                                 "Failed to DMA remap %lu pages\n",
+                                 page_count);
+                        goto err_pages;
+                }
+        }
 
         if (i915_gem_object_needs_bit17_swizzle(obj))
                 i915_gem_object_do_bit_17_swizzle(obj, st);