Re: [PATCH] x86-64: pci-gart iommu sg chaining zeroes wrong sg.

From: FUJITA Tomonori
Date: Thu Sep 27 2007 - 12:47:48 EST


On Fri, 28 Sep 2007 01:38:27 +0900
FUJITA Tomonori <tomof@xxxxxxx> wrote:

> This patch is for Jens' block tree (sg chaining branch).
>
> I don't have the hardware but this looks like a bug.
>
> ---
> From: FUJITA Tomonori <fujita.tomonori@xxxxxxxxxxxxx>
> Subject: [PATCH] x86-64: pci-gart iommu sg chaining zeroes a wrong sg's dma_length
>
> Needs to zero the end of the list.
>
> Signed-off-by: FUJITA Tomonori <fujita.tomonori@xxxxxxxxxxxxx>
> ---
> arch/x86_64/kernel/pci-gart.c | 3 ++-
> 1 files changed, 2 insertions(+), 1 deletions(-)
>
> diff --git a/arch/x86_64/kernel/pci-gart.c b/arch/x86_64/kernel/pci-gart.c
> index 27b7db4..a4151a7 100644
> --- a/arch/x86_64/kernel/pci-gart.c
> +++ b/arch/x86_64/kernel/pci-gart.c
> @@ -425,9 +425,10 @@ int gart_map_sg(struct device *dev, struct scatterlist *sg, int nents, int dir)
> if (dma_map_cont(start_sg, i - start, sgmap, pages, need) < 0)
> goto error;
> out++;
> + sgmap = sg_next(sgmap);
> flush_gart();
> if (out < nents)
> - ps->dma_length = 0;
> + sgmap->dma_length = 0;
> return out;

Sorry, it should be:


diff --git a/arch/x86_64/kernel/pci-gart.c b/arch/x86_64/kernel/pci-gart.c
index 27b7db4..cfcc84e 100644
--- a/arch/x86_64/kernel/pci-gart.c
+++ b/arch/x86_64/kernel/pci-gart.c
@@ -426,8 +426,10 @@ int gart_map_sg(struct device *dev, struct scatterlist *sg, int nents, int dir)
goto error;
out++;
flush_gart();
- if (out < nents)
- ps->dma_length = 0;
+ if (out < nents) {
+ sgmap = sg_next(sgmap);
+ sgmap->dma_length = 0;
+ }
return out;

error:
-
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