drm/i915: unpin backing storage in dmabuf_unmap
authorDaniel Vetter <daniel.vetter@ffwll.ch>
Thu, 8 Aug 2013 07:10:37 +0000 (09:10 +0200)
committerDave Airlie <airlied@gmail.com>
Mon, 19 Aug 2013 03:24:54 +0000 (13:24 +1000)
commiteb91626ac4b9af3d5602a7db888b8bc4cb23eb3b
treeb7edc496796b7789b912944ef3f766a20f1a6e4a
parentd2b2c08456d12a9914c87cef479b2ec2ab30337f
drm/i915: unpin backing storage in dmabuf_unmap

This fixes a WARN in i915_gem_free_object when the
obj->pages_pin_count isn't 0.

v2: Add locking to unmap, noticed by Chris Wilson. Note that even
though we call unmap with our own dev->struct_mutex held that won't
result in an immediate deadlock since we never go through the dma_buf
interfaces for our own, reimported buffers. But it's still easy to
blow up and anger lockdep, but that's already the case with our ->map
implementation. Fixing this for real will involve per dma-buf ww mutex
locking by the callers. And lots of fun. So go with the duct-tape
approach for now.

Cc: Chris Wilson <chris@chris-wilson.co.uk>
Reported-by: Maarten Lankhorst <maarten.lankhorst@canonical.com>
Cc: Maarten Lankhorst <maarten.lankhorst@canonical.com>
Tested-by: Armin K. <krejzi@email.com> (v1)
Tested-by: Dave Airlie <airlied@redhat.com>
Acked-by: Maarten Lankhorst <maarten.lankhorst@canonical.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Dave Airlie <airlied@gmail.com>
drivers/gpu/drm/i915/i915_gem_dmabuf.c