drm/i915: Drop obj.page_pin_count after a failed vma->set_pages()

Before we attempt to set_pages on the vma, we claim a
obj.pages_pin_count for it. If we subsequently fail to set the pages on
the vma, we need to drop our pinning before returning the error.

Reported-by: Matthew Auld <matthew.auld@intel.com>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Matthew Auld <matthew.auld@intel.com>
Reviewed-by: Matthew Auld <matthew.auld@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20191015093915.3995-1-chris@chris-wilson.co.uk

diff --git a/drivers/gpu/drm/i915/i915_vma.c b/drivers/gpu/drm/i915/i915_vma.c
index 9fdcd4e..7d93625 100644 (file)
--- a/drivers/gpu/drm/i915/i915_vma.c
+++ b/drivers/gpu/drm/i915/i915_vma.c
@@ -802,8 +802,11 @@ static int vma_get_pages(struct i915_vma *vma)
                }
 
                err = vma->ops->set_pages(vma);
-               if (err)
+               if (err) {
+                       if (vma->obj)
+                               i915_gem_object_unpin_pages(vma->obj);
                        goto unlock;
+               }
        }
        atomic_inc(&vma->pages_count);