Messages in this thread |  | | | Date | Sun, 11 Jan 2009 09:08:58 +0100 | | From | Joerg Roedel <> | | Subject | Re: [PATCH 15/16] dma-debug: x86 architecture bindings |
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On Sun, Jan 11, 2009 at 03:25:47PM +0900, FUJITA Tomonori wrote: > On Fri, 9 Jan 2009 17:19:29 +0100 > Joerg Roedel <joerg.roedel@amd.com> wrote: > > > Impact: make use of DMA-API debugging code in x86 > > > > Signed-off-by: Joerg Roedel <joerg.roedel@amd.com> > > --- > > arch/x86/Kconfig | 1 + > > arch/x86/include/asm/dma-mapping.h | 30 ++++++++++++++++++++++++++---- > > arch/x86/kernel/pci-dma.c | 5 +++++ > > 3 files changed, 32 insertions(+), 4 deletions(-) > > > > diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig > > index 862adb9..68a806c 100644 > > --- a/arch/x86/Kconfig > > +++ b/arch/x86/Kconfig > > @@ -39,6 +39,7 @@ config X86 > > select HAVE_GENERIC_DMA_COHERENT if X86_32 > > select HAVE_EFFICIENT_UNALIGNED_ACCESS > > select USER_STACKTRACE_SUPPORT > > + select HAVE_DMA_API_DEBUG > > > > config ARCH_DEFCONFIG > > string > > diff --git a/arch/x86/include/asm/dma-mapping.h b/arch/x86/include/asm/dma-mapping.h > > index 4035357..939d5b3 100644 > > --- a/arch/x86/include/asm/dma-mapping.h > > +++ b/arch/x86/include/asm/dma-mapping.h > > @@ -7,6 +7,7 @@ > > */ > > > > #include <linux/scatterlist.h> > > +#include <linux/dma-debug.h> > > #include <asm/io.h> > > #include <asm/swiotlb.h> > > #include <asm-generic/dma-coherent.h> > > @@ -93,9 +94,12 @@ dma_map_single(struct device *hwdev, void *ptr, size_t size, > > int direction) > > { > > struct dma_mapping_ops *ops = get_dma_ops(hwdev); > > + dma_addr_t addr; > > > > BUG_ON(!valid_dma_direction(direction)); > > - return ops->map_single(hwdev, virt_to_phys(ptr), size, direction); > > + addr = ops->map_single(hwdev, virt_to_phys(ptr), size, direction); > > + debug_map_single(hwdev, ptr, size, direction, addr); > > + return addr; > > What happens if ops->map_single fails? > > Seems that debug_map_single doesn't check the dma mapping fails. So it > allocates a new entries and nobody frees it?
Ah true. The debug_map_single function has to check for dma_mapping_error. Same is true for debug_map_sg.
> Another problem is that what happens if ops->map_single succeeds but > debug_map_single fails? Seems that it gives a false warning.
No, this can not happen. If the code fails it disables itself so no more warnings will be printed.
Joerg
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