xen-swiotlb: Fix wrong panic.

commit ab2a47bd24 upstream.

Propagate the baremetal git commit "swiotlb: fix wrong panic"
(fba99fa38b) in the Xen-SWIOTLB version.
wherein swiotlb's map_page wrongly calls panic() when it can't find
a buffer fit for device's dma mask.  It should return an error instead.

Devices with an odd dma mask (i.e.  under 4G) like b44 network card hit
this bug (the system crashes):

http://marc.info/?l=linux-kernel&m=129648943830106&w=2

If xen-swiotlb returns an error, b44 driver can use the own bouncing
mechanism.

Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This commit is contained in:
Konrad Rzeszutek Wilk
2011-07-22 12:51:48 -04:00
committed by Greg Kroah-Hartman
parent 50bac9ce73
commit a19d5a89a4

View File

@@ -278,9 +278,10 @@ dma_addr_t xen_swiotlb_map_page(struct device *dev, struct page *page,
/*
* Ensure that the address returned is DMA'ble
*/
if (!dma_capable(dev, dev_addr, size))
panic("map_single: bounce buffer is not DMA'ble");
if (!dma_capable(dev, dev_addr, size)) {
swiotlb_tbl_unmap_single(dev, map, size, dir);
dev_addr = 0;
}
return dev_addr;
}
EXPORT_SYMBOL_GPL(xen_swiotlb_map_page);