Re: [RFC] disable_irq()/enable_irq() semantics and ide-probe.c

[Manfred Spraul <manfred@colorfullife.com>]

Linus wrote:

>Nobody has ever really complained, but if anybody 
>ever wants to do this, then the way to do it would be to
>
> - find out the irq
> - disable it
> - request the irq
> - enable the PCI routing for it
> - set up the device
> - enable the irq
>
I'd like to use that for nic shutdown for natsemi:

    disable_irq();
    shutdown_nic();
    free_irq();
    enable_irq();

The irq handler touches registers that restart the nic. Right now I use 
a np->hands_off variable to avoid that.

But I don't know if all systems can support atomic request_irq/free_irq 
calls. request_irq creates /proc/irq/x/cpu_affinity, and I could imagine 
that on some archs it might have perform IPIs to reconfigure the irq 
controller of a remote node.

--
    Manfred