e385ea63f4
At91_mci is abusing dma_free_coherent(), which may not be called with IRQs disabled. I saw "mkfs.ext3" on an MMC card objecting voluminously as each write completed: WARNING: at arch/arm/mm/consistent.c:368 dma_free_coherent+0x2c/0x224() [<c002726c>] (dump_stack+0x0/0x14) from [<c00387d4>] (warn_on_slowpath+0x4c/0x68) [<c0038788>] (warn_on_slowpath+0x0/0x68) from [<c0028768>] (dma_free_coherent+0x2c/0x224) r6:00008008 r5:ffc06000 r4:00000000 [<c002873c>] (dma_free_coherent+0x0/0x224) from [<c01918ac>] (at91_mci_irq+0x374/0x420) [<c0191538>] (at91_mci_irq+0x0/0x420) from [<c0065d9c>] (handle_IRQ_event+0x2c/0x6c) ... This bug has been around for a LONG time. The MM warning is from late 2005, but the driver merged a year later ... so I'm puzzled why nobody noticed this before now. The fix involves noting that this buffer shouldn't be DMA-coherent; it's just used for normal DMA writes. So replace it with standard kmalloc() buffering and DMA mapping calls. This is the quickie fix. A better one would not rely on allocating large bounce buffers. (Note that dma_alloc_coherent could have failed too, but that case was ignored... kmalloc is a bit more likely to fail though.) Signed-off-by: David Brownell <dbrownell@users.sourceforge.net> Acked-by: Pierre Ossman <drzeus-mmc@drzeus.cx> Cc: Andrew Victor <linux@maxim.org.za> Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com> Cc: Russell King <rmk@arm.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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