dma-debugs wrongly assumes that no multiple DMA transfers are performed against the same dma address on one device at the same time. However it's true only with hardware IOMMUs. For example, an application can easily send the same buffer twice with different lengths to one device by using DIO and AIO. If these requests are not unmapped in the same order in which they were mapped, hash_bucket_find() finds a wrong entry and gives a false warning. We should fix this before 2.6.30 release. Seems that there is no easy way to fix it. I think that it's better to just disable dma-debug for now. Torsten Kaiser found this bug with the RAID1 configuration: http://marc.info/?t=124336541900008&r=1&w=2 Reported-by: Torsten Kaiser <just.for.lkml@xxxxxxxxxxxxxx> Signed-off-by: FUJITA Tomonori <fujita.tomonori@xxxxxxxxxxxxx> --- arch/sh/Kconfig | 1 - arch/x86/Kconfig | 1 - 2 files changed, 0 insertions(+), 2 deletions(-) diff --git a/arch/sh/Kconfig b/arch/sh/Kconfig index e7390dd..4fb19d7 100644 --- a/arch/sh/Kconfig +++ b/arch/sh/Kconfig @@ -14,7 +14,6 @@ config SUPERH select HAVE_GENERIC_DMA_COHERENT select HAVE_IOREMAP_PROT if MMU select HAVE_ARCH_TRACEHOOK - select HAVE_DMA_API_DEBUG help The SuperH is a RISC processor targeted for use in embedded systems and consumer electronics; it was also used in the Sega Dreamcast diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index a6efe0a..b3cf490 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -42,7 +42,6 @@ config X86 select HAVE_GENERIC_DMA_COHERENT if X86_32 select HAVE_EFFICIENT_UNALIGNED_ACCESS select USER_STACKTRACE_SUPPORT - select HAVE_DMA_API_DEBUG select HAVE_KERNEL_GZIP select HAVE_KERNEL_BZIP2 select HAVE_KERNEL_LZMA -- 1.6.0.6 -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
