Messages in this thread | | | Subject | Re: more iommu sg merging fallout | From | FUJITA Tomonori <> | Date | Tue, 19 Feb 2008 19:57:58 +0900 |
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On Sun, 17 Feb 2008 23:41:42 -0800 (PST) David Miller <davem@davemloft.net> wrote:
> From: FUJITA Tomonori <tomof@acm.org> > Date: Sat, 16 Feb 2008 15:03:43 +0900 > > > [PATCH] sparc64: make IOMMU code respect the segment boundary limits > > > > Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp> > > Looks good, but I think it will break sound for some ALI chips. > > Please see arch/sparc64/kernel/pci.c:ali_sound_dma_hack() > and it's caller pci_dma_supported().
Could you explain the problem a little more?
The shift argument is only used as an offset when iommu-helper decides whether a memory area (index plus npages) spanning LLD's segment boudnary size or not.
For example, if a device's segment boudary size is 64K, the helper see the following value is larger than 64K or not:
((the offset + index of the IOMMU table) ((64K / 8K) - 1) + npages
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