Merge branch 'libnvdimm-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdim...

[karo-tx-linux.git] / drivers / gpu / drm / i915 / i915_gem_userptr.c

diff --git a/drivers/gpu/drm/i915/i915_gem_userptr.c b/drivers/gpu/drm/i915/i915_gem_userptr.c
index 8fd431bcdfd3a33ffb6afda7a1584b44e33d8296..a96b9006a51e5a893eea071d1d638ef3c2cef6fb 100644 (file)
--- a/drivers/gpu/drm/i915/i915_gem_userptr.c
+++ b/drivers/gpu/drm/i915/i915_gem_userptr.c
@@ -804,7 +804,10 @@ static const struct drm_i915_gem_object_ops i915_gem_userptr_ops = {
  * Also note, that the object created here is not currently a "first class"
  * object, in that several ioctls are banned. These are the CPU access
  * ioctls: mmap(), pwrite and pread. In practice, you are expected to use
- * direct access via your pointer rather than use those ioctls.
+ * direct access via your pointer rather than use those ioctls. Another
+ * restriction is that we do not allow userptr surfaces to be pinned to the
+ * hardware and so we reject any attempt to create a framebuffer out of a
+ * userptr.
  *
  * If you think this is a good interface to use to pass GPU memory between
  * drivers, please use dma-buf instead. In fact, wherever possible use