Commit fba99fa3 authored Feb 25, 2011 by FUJITA Tomonori Committed by Linus Torvalds Feb 25, 2011

swiotlb: fix wrong panic

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

Reported-by: Chuck Ebbert <cebbert@redhat.com>
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Tested-by: Arkadiusz Miskiewicz <arekm@maven.pl>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

parent f8407f26

lib/swiotlb.c

+4 −2

Original line number	Diff line number	Diff line
		@@ -686,8 +686,10 @@ dma_addr_t 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 = swiotlb_virt_to_bus(dev, io_tlb_overflow_buffer);
		}

		return dev_addr;
		}

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