Commit 2912282c authored Aug 22, 2009 by Jiri Slaby Committed by Greg Kroah-Hartman Sep 23, 2009

USB: make usb_buffer_map_sg consistent with doc



usb_buffer_map_sg should return negative on error according to
its documentation. But dma_map_sg returns 0 on error. Take this
into account and return -ENOMEM in such situation.

While at it, return -EINVAL instead of -1 when wrong input is
passed in.

If this wasn't done, usb_sg_* operations used after usb_sg_init
which returned 0 may cause oopses/deadlocks since we don't init
structures/entries, esp. completion and status entry.

Signed-off-by: Jiri Slaby <jirislaby@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

parent a448c9d8

drivers/usb/core/usb.c

+2 −2

Original line number	Diff line number	Diff line
		@@ -914,11 +914,11 @@ int usb_buffer_map_sg(const struct usb_device *dev, int is_in,
		\|\| !(bus = dev->bus)
		\|\| !(controller = bus->controller)
		\|\| !controller->dma_mask)
		return -1;
		return -EINVAL;

		/* FIXME generic api broken like pci, can't report errors */
		return dma_map_sg(controller, sg, nents,
		is_in ? DMA_FROM_DEVICE : DMA_TO_DEVICE);
		is_in ? DMA_FROM_DEVICE : DMA_TO_DEVICE) ? : -ENOMEM;
		}
		EXPORT_SYMBOL_GPL(usb_buffer_map_sg);

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