Eric Lee / linux-smarc-t335x-v3.2

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Commit fba99fa38b023224680308a482e12a0eca87e4e1

Authored by FUJITA Tomonori
Committed by Linus Torvalds
1 parent f8407f26b4

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>

Showing 1 changed file with 4 additions and 2 deletions Side-by-side Diff

... ... @@ -686,8 +686,10 @@
686 686 /*
687 687 * Ensure that the address returned is DMA'ble
688 688 */
689   - if (!dma_capable(dev, dev_addr, size))
690   - panic("map_single: bounce buffer is not DMA'ble");
  689 + if (!dma_capable(dev, dev_addr, size)) {
  690 + swiotlb_tbl_unmap_single(dev, map, size, dir);
  691 + dev_addr = swiotlb_virt_to_bus(dev, io_tlb_overflow_buffer);
  692 + }
691 693  
692 694 return dev_addr;
693 695 }