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Commit eb91626a authored by Daniel Vetter's avatar Daniel Vetter Committed by Dave Airlie
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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: default avatarMaarten Lankhorst <maarten.lankhorst@canonical.com>
Cc: Maarten Lankhorst <maarten.lankhorst@canonical.com>
Tested-by: Armin K. <krejzi@email.com> (v1)
Tested-by: default avatarDave Airlie <airlied@redhat.com>
Acked-by: default avatarMaarten Lankhorst <maarten.lankhorst@canonical.com>
Signed-off-by: default avatarDaniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: default avatarDave Airlie <airlied@gmail.com>
parent d2b2c084

drivers/gpu/drm/i915/i915_gem_dmabuf.c

+8 −0
Original line number Diff line number Diff line
@@ -85,9 +85,17 @@ static void i915_gem_unmap_dma_buf(struct dma_buf_attachment *attachment, 
				   struct sg_table *sg,

				   enum dma_data_direction dir)

{

	struct drm_i915_gem_object *obj = attachment->dmabuf->priv;



	mutex_lock(&obj->base.dev->struct_mutex);



	dma_unmap_sg(attachment->dev, sg->sgl, sg->nents, dir);

	sg_free_table(sg);

	kfree(sg);



	i915_gem_object_unpin_pages(obj);



	mutex_unlock(&obj->base.dev->struct_mutex);

}



static void i915_gem_dmabuf_release(struct dma_buf *dma_buf)