Re: [Bug 487894] New: sky2 0000:06:00.0: DMA-API: device driverfrees DMA memory with different size

[FUJITA Tomonori]

On Thu, 2 Apr 2009 13:18:39 +0200
Joerg Roedel <joerg.roedel@xxxxxxx> wrote:

> On Thu, Apr 02, 2009 at 08:06:26PM +0900, FUJITA Tomonori wrote:
> > On Thu, 2 Apr 2009 12:54:15 +0200
> > Joerg Roedel <joerg.roedel@xxxxxxx> wrote:
> > 
> > > On Wed, Apr 01, 2009 at 11:02:45AM -0700, Stephen Hemminger wrote:
> > > > 
> > > > The sky2 driver uses pci_unmap_len and pci_unmap_len_set which on 32 bit
> > > > platforms are meaningless so they are stubbed out. 
> > > > Basically, DMA-API checks are wrong/bogus to enforce on 32bit x86 as is.
> > > 
> > > As far as I know the VT-d driver is available on 32 bit x86 too. So this should
> > > not always be a nop.
> > 
> > VT-d is available on only x86_64.
> 
> At least there was a patch to enable it on 32 bit too. See
> 
> https://lists.linux-foundation.org/pipermail/iommu/2009-February/001080.html
> 
> It seems not to be upstream yet.

It's not in upstream.


Anyway, about the original problem, I think that the best fix is not
to stub out the dma API; using the dma API properly is always a good
thing.
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