Re: VT-d and x2apic: broken resume after suspend to ram

[Peter Senna Tschudin]

On Fri, Nov 1, 2013 at 2:07 PM, Joerg Roedel <joro@xxxxxxxxxx> wrote:
> Hi Peter,
>
> On Fri, Nov 01, 2013 at 01:37:36PM +0100, Peter Senna Tschudin wrote:
>> I have one notebook that is failing to resume after suspend to ram.
>> I've filled a bug report back on the 2.6.41 days:
>>
>> https://bugzilla.redhat.com/show_bug.cgi?id=787299
>>
>> The issue is that trying to resume after suspending to ram freezes the
>> computer. The resume starts well, but then it hangs.
>>
>> Yesterday I found that this may be related to VT-d / x2apic. If I
>> disable VT-d on the BIOS, suspend / resume works fine. If I enable
>> VT-d and pass nox2apic as boot parameter to Kernel suspend and resume
>> works fine. I would like some pointers to fix this issue. Can you help
>> me?
>>
>> Only when I have VT-d enabled, dmesg gives me additional output:
>> [    0.023913] IOAPIC id 2 under DRHD base  0xfed91000 IOMMU 1
>> [    0.024080] Enabled IRQ remapping in x2apic mode
>> [    0.024081] Enabling x2apic
>> [    0.024082] Enabled x2apic
>> [    0.024087] Switched APIC routing to cluster x2apic.
>>
>> The notebook is Toshiba R830-10p with i7-2620M.
>
> Which kernels have you tried? Does it happen with all of them or is
> there a kernel-version where this started?

I'm using 3.11.6-200.fc19.x86_64. I always had VT-d enabled, and
suspend / resume never worked on Linux. I did not know that disabling
VT-d could be a workaround to the resume issue until yesterday.

Does this have anything in common to:
https://bugzilla.redhat.com/show_bug.cgi?id=752613

>
>
>         Joerg
>
>



-- 
Peter
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