Re: Ask help about pre_init_apic_IRQ0()

Thomas Gleixner
2014-09-12T08:26:32Z

On Fri, 12 Sep 2014, Andy Shevchenko wrote:
> On Thu, 2014-09-11 at 23:59 +0200, Thomas Gleixner wrote:

> > > > x86_intel_mid_timer=apbt_only
>
> w/o patch
>
> [ 0.000000] Early APIC setup for system timer0
> [ 0.000000] ------------[ cut here ]------------
> [ 0.000000] WARNING: CPU: 0 PID: 0 at
> arch/x86/kernel/apic/apic.c:1393 setup_local_APIC+0x20c/0x2d9()
>
> ...and stuck a bit later

Right, because there is no apbt timer in that machine and the
commandline tells the kernel to use it and ignore the local apic
timer.

> > > > or
> > > > x86_intel_mid_timer=lapic_and_apbt
> > >
> > > [ 0.116858] BUG: unable to handle kernel NULL pointer dereference at
> > > 0000003a
> > > [ 0.123820] IP: [<c1071c0e>] setup_irq+0xf/0x4d
> > > ...
> > >
>
> w/o patch
>
> [ 0.000000] Early APIC setup for system timer0
> [ 0.000000] ------------[ cut here ]------------
> [ 0.000000] WARNING: CPU: 0 PID: 0 at
> arch/x86/kernel/apic/apic.c:1393 setup_local_APIC+0x20c/0x2d9()
>
> ...and boots normally

Right, because it uses the local apic timer later on.

Thanks for providing the data! I'll queue a removal of this mess.

Thanks,

tglx