Re: sti() freezes the kernel

[Yoann Allain <yallain@avilinks.com>]

Ralf Baechle a écrit :

> On Mon, Oct 17, 2005 at 10:48:46AM +0200, Yoann Allain wrote:
>
>  
>
> > I'm actually trying to start a 2.4 kernel on our new card.
> > The kernel freezes when enabling interrupts with sti() in start_kernel() 
> > (just before calculating BogoMips...).
> > This looks like an interrupts is up when enabling so that it stops the 
> > MIPS and freezes the kernel.
> > I'm looking after this interrupt but I would like to know if there could 
> > be any others reasons for my kernel to freeze when doing a call to sti();
> >    
> This is a fairly scenario and as you suspect it's being caused by interrupt
> problems, such as interrupts still pending from the firmware, being
> not initialized at all or similar.
>
>  Ralf
>  
Since last mail I played with the interrupt masks (IM - bits 15-8 in 
MIPS status register) . From the MIPS cause register, it seems that the 
bit 15 (hardware interrupt 5 or timer interrupt) is the originator of 
the freezing interrupt. And the exception code shown for this interrupt 
is 6 corresponding to a Bus error exception. I think there's a pointer 
to the interrupt handler not correctly initialized. So that the 
interrupt makes a jump to nowhere.
The Bus monitors are not enabled, this is perhaps why the kernel freezes 
instead of printing the details of the exception.
Am I right?