Re: [RFC][Intel-IOMMU] Fix for IOMMU early crash

["Keshavamurthy, Anil S" <anil.s.keshavamurthy@intel.com>]

On Mon, Sep 10, 2007 at 11:25:43PM +0300, Muli Ben-Yehuda wrote:
> On Tue, Sep 11, 2007 at 10:42:31AM -0700, Keshavamurthy, Anil S wrote:
> 
> > Yes, I agree that pci_dev->sysdata can;t be removed. Even we (IOMMU)
> > were dependent on this field but somehow this field is being
> > overwritten to point to pci_bus's->sysdata and hence IOMMU was
> > failing. Earlier it was overwritten to NULL and hence we were not
> > failing but now it is overwritten to non-NULL and hence we fail.
> 
> Do you know which commit caused that change?
> 
> > My therory is that we don;t need to copy pci_bus's->sysdata to 
> > pci_dev's->sysdata. Below patch solves my problem.
> > Any objection to below patch?
> 
> I will give it a spin to verify it works for me, but in general I am
> wary of making such changes unless we can verify (read: audit) that
> they have no adverse side effects *on all architectures*.
Thanks Muli for your help here. I tested on x86_64 and saw no
issues. Looking at the code, pci_dev's->sysdata becomes useless 
if the intent here is to keep a copy of it's bus's->sysdata as
the same can be obtained from pci_dev->bus->sysdata.

Thanks,
Anil