Re: [PATCH] 2.6.18-rt7: PowerPC: fix breakage in threaded fasteoitype IRQ handlers

From: Benjamin Herrenschmidt
Date: Mon Nov 20 2006 - 15:10:18 EST


On Mon, 2006-11-20 at 17:56 +0100, Ingo Molnar wrote:
> * Sergei Shtylyov <sshtylyov@xxxxxxxxxxxxx> wrote:
>
> > >on PPC64, 'get the vector' initiates an ACK as well - is that done
> > >before handle_irq() is done?
> >
> > Exactly. How else do_IRQ() would know the vector?
>
> the reason i'm asking is that in this case masking is a bit late at this
> point and there's a chance for a repeat interrupt.

What do you mean by a bit late ?

You can't mask before you know what interrupt occured so you don't
really have a choice there :-) I'm pretty sure that mask + eoi is what
Apple does on Darwin too though.

Cheers,
Ben.


-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/