Re: 2.6.23-rc2: WARNING: at kernel/irq/resend.c:70 check_irq_resend()

[Jarek Poplawski]

On Fri, Aug 10, 2007 at 10:30:50AM +0200, Ingo Molnar wrote:
> 
> * Jarek Poplawski <jarkao2@xxxxx> wrote:
> 
> > > Hmm. This solution is still just pampering over the real problem. 
> > > The delayed disable just re-sends level interrupts unnecessarily. I 
> > > have a fix (needs some testing) for this, which I send out tomorrow, 
> > > when I'm really back from vacation.
> > > 
> > > But suppressing the resend is not fixing the driver problem. The 
> > > problem can show up with spurious interrupts and with interrupts on 
> > > a shared PCI interrupt line at any time. It just might take weeks 
> > > instead of minutes.
> > 
> > Doesn't it look like a little change of mind? [...]
> 
> what change of mind do you mean exactly?
> 
> > [...] Well, there are probably (but need more testing) two other 
> > solutions: _SW_RESEND and disabling without delay for levels only...
> 
> IIRC Marcin tested software-resend and it didnt fix the hang. That 
> strongly points in the direction of a driver bug (or a genirq bug) being 
> made more prominent by the genirq change - not any hardware detail such 
> as the APIC vector-retrigger sequence.
> 
> While we'd like to see the suspected driver bug (or any higher level 
> genirq bug) fixed, we'll undo the effect of the genirq change (because 
> it is causing a regression). We'll also add a separate, optional 
> irq-debugging feature that generates high-rate interrupts on any shared 
> irq line. (and thus artificially stresses the robustness of the driver 
> and the genirq layer against spurious interrupts.)

Not exactly so... I've send modified version of your software-resend
patch, and it seems to work OK.

Jarek P.