Re: [RFC patch] return early if all dmar HW unit ignored

From: David Woodhouse
Date: Tue Aug 04 2009 - 03:10:12 EST


On Fri, 2009-07-31 at 16:29 +0800, Luming Yu wrote:
> Hello list,
>
> When debugging an IOMMU problem, I noticed it should be much more safe
> to return early than late if all remapping HW unit are ignored.
> To figure out what device causes the iommu problem on my linux box:
> hp-compaq dc7800, I tried to mark all dmar HW
> unit ignored,but still got a lot of unxepcted dmar_fault. So I think
> the proposed patch make sense. The next step is to
> add a boot option to make dmar HW units selectable enable/disable individually.

Why were you seeing faults if all dmar units were ignored? Surely that
shouldn't happen?

This patch doesn't make a lot of sense on its own -- can you show what
you were intending to do as the 'next step'?

--
David Woodhouse Open Source Technology Centre
David.Woodhouse@xxxxxxxxx Intel Corporation

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/