From: FUJITA Tomonori <[email protected]> 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 <[email protected]> Signed-off-by: FUJITA Tomonori <[email protected]> Tested-by: Arkadiusz Miskiewicz <[email protected]> Cc: <[email protected]> Signed-off-by: Andrew Morton <[email protected]> --- lib/swiotlb.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff -puN lib/swiotlb.c~swiotlb-fix-wrong-panic lib/swiotlb.c --- a/lib/swiotlb.c~swiotlb-fix-wrong-panic +++ a/lib/swiotlb.c @@ -686,8 +686,10 @@ dma_addr_t swiotlb_map_page(struct devic /* * 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; } _ _______________________________________________ stable mailing list [email protected] http://linux.kernel.org/mailman/listinfo/stable
