drm/i915: Allow ggtt lookups to not WARN

To be able to effectively use the GGTT object lookup function, we don't
want to warn when there is no GGTT mapping. Let the caller deal with it
instead.

Originally, I had intended to have this behavior, and has not
introduced the WARN. It was introduced during review with the addition
of the follow commit

commit 5c2abbeab798154166d42fce4f71790caa6dd9bc
Author: Ben Widawsky <benjamin.widawsky@intel.com>
Date:   Tue Sep 24 09:57:57 2013 -0700

    drm/i915: Provide a cheap ggtt vma lookup

Signed-off-by: Ben Widawsky <ben@bwidawsk.net>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index 1f89a076e4f53ee72c362a6e556889e150794569..360b68fbef6df0f252c142e563380192a2019bcc 100644 (file)
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -5073,7 +5073,7 @@ struct i915_vma *i915_gem_obj_to_ggtt(struct drm_i915_gem_object *obj)
                return NULL;
 
        vma = list_first_entry(&obj->vma_list, typeof(*vma), vma_link);
-       if (WARN_ON(vma->vm != obj_to_ggtt(obj)))
+       if (vma->vm != obj_to_ggtt(obj))
                return NULL;
 
        return vma;