Re: 2.6.29: can't resume from suspend with DMAR (intel iommu)enabled

[David Woodhouse]

On Tue, 2009-03-24 at 21:32 +0100, Ingo Molnar wrote:
> (Cc:s added)
> 
> * Andrew Lutomirski <amluto@xxxxxxxxx> wrote:
> 
> > On vanilla 2.6.29 (on Ubuntu 8.10), on a Lenovo x200s, my system 
> > is completely hosed on resume.  It appears that even hard disk IO 
> > didn't work (trying to do *anything* including getting a dmesg 
> > trace just spewed sda io errors to the console).  Hence no trace.  
> > I did an alt-sysrq-b and the screen went blank and the machine 
> > just started beeping at me.
> > 
> > Resume works much better with intel_iommu=off.  (I remember seeing 
> > a patch go by that purported to fix resume with IOMMU enabled, but 
> > it didn't work for me.)
> > 
> > I'd be happy to try to make a better bug report if anyone has any 
> > bright ideas.
> 
> i have a Lenovo T500 that does not even boot with with DMAR enabled 
> in the BIOS (it's default-off), i get this panic in early bootup:
> 
>     DMAR hardware is malfunctioning

Can you show me the output of the pr_debug() statement at dmar.c:543 (in
alloc_iommu()? 

And bring me the head of a BIOS author.

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

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