Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 6b607e3a authored by Daniel Vetter's avatar Daniel Vetter Committed by Sumit Semwal
Browse files

dma-buf: don't hold the mutex around map/unmap calls 



The mutex protects the attachment list and hence needs to be held
around the callbakc to the exporters (optional) attach/detach
functions.

Holding the mutex around the map/unmap calls doesn't protect any
dma_buf state. Exporters need to properly protect any of their own
state anyway (to protect against calls from their own interfaces).
So this only makes the locking messier (and lockdep easier to anger).

Therefore let's just drop this.

v2: Rebased on top of latest dma-buf-next git.

Signed-off-by: default avatarDaniel Vetter <daniel.vetter@ffwll.ch>
Reviewed-by: default avatarRob Clark <rob.clark@linaro.org>
Signed-off-by: default avatarSumit Semwal <sumit.semwal@linaro.org>
parent f9a24d1a

drivers/base/dma-buf.c

+0 −5
Original line number Original line Diff line number Diff line
@@ -258,9 +258,7 @@ struct sg_table *dma_buf_map_attachment(struct dma_buf_attachment *attach, 
	if (WARN_ON(!attach || !attach->dmabuf))

	if (WARN_ON(!attach || !attach->dmabuf))

		return ERR_PTR(-EINVAL);

		return ERR_PTR(-EINVAL);





	mutex_lock(&attach->dmabuf->lock);

	sg_table = attach->dmabuf->ops->map_dma_buf(attach, direction);

	sg_table = attach->dmabuf->ops->map_dma_buf(attach, direction);

	mutex_unlock(&attach->dmabuf->lock);





	return sg_table;

	return sg_table;

}

}
@@ -282,10 +280,7 @@ void dma_buf_unmap_attachment(struct dma_buf_attachment *attach, 
	if (WARN_ON(!attach || !attach->dmabuf || !sg_table))

	if (WARN_ON(!attach || !attach->dmabuf || !sg_table))

		return;

		return;





	mutex_lock(&attach->dmabuf->lock);

	attach->dmabuf->ops->unmap_dma_buf(attach, sg_table,

	attach->dmabuf->ops->unmap_dma_buf(attach, sg_table,

						direction);

						direction);

	mutex_unlock(&attach->dmabuf->lock);



}

}

EXPORT_SYMBOL_GPL(dma_buf_unmap_attachment);
 
EXPORT_SYMBOL_GPL(dma_buf_unmap_attachment);

include/linux/dma-buf.h

+1 −1
Original line number Original line Diff line number Diff line
@@ -88,7 +88,7 @@ struct dma_buf { 
	struct file *file;

	struct file *file;

	struct list_head attachments;

	struct list_head attachments;

	const struct dma_buf_ops *ops;

	const struct dma_buf_ops *ops;

	/* mutex to serialize list manipulation and other ops */

	/* mutex to serialize list manipulation and attach/detach */

	struct mutex lock;

	struct mutex lock;

	void *priv;

	void *priv;

};

};