Messages in this thread | | | Date | Sat, 18 Apr 2009 09:24:14 +0200 | From | Ingo Molnar <> | Subject | Re: [PATCH 3/5] x86, intr-remap: enable interrupt remapping early |
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* Suresh Siddha <suresh.b.siddha@intel.com> wrote:
> On Fri, 2009-04-17 at 07:13 -0700, Ingo Molnar wrote: > > * Weidong Han <weidong.han@intel.com> wrote: > > > > > --- a/arch/x86/kernel/apic/apic.c > > > +++ b/arch/x86/kernel/apic/apic.c > > > @@ -118,6 +118,8 @@ static int x2apic_preenabled; > > > static int disable_x2apic; > > > static __init int setup_nox2apic(char *str) > > > { > > > + if (x2apic_enabled()) > > > + panic("Bios already enabled x2apic, can't enforce nox2apic"); > > > > Could you please turn that into something like: > > I have couple of patches cleaning these up(including some > warnings). I will post them shortly.
ok!
> > > +ir_failed: > > > + if (x2apic_preenabled) > > > + panic("x2apic enabled by bios. But IR enabling failed"); > > > > What is the likelyhood that we can continue in compat mode? If > > there's some chance, we should rather print a KERN_WARNING and > > should try to continue. If IRQs are not coming we'll hang shortly > > afterwards anyway. > > Typically only on high end platforms we will see x2apic enabled by > BIOS before OS handover. And in these cases, BIOS should have > already enabled interrupt-remapping in extended interrupt mode, > before handing over control to OS. If the extended interrupt mode > is set, HW will block the compatibility format interrupts anyway. > And I think its better to panic rather than hanging at random > places(depending on which interrupts are already in remapped > format and which are not). This way, it will be easy for anyone to > figure out what is happening.
fair enough.
Ingo
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