Re: [PATCH] I/O APIC: AEOI timer acknowledgement clean-ups

From: Ingo Molnar
Date: Mon May 19 2008 - 08:27:18 EST

* Maciej W. Rozycki <macro@xxxxxxxxxxxxxx> wrote:

> The code that used to be in do_slow_gettimeoffset() that relied on the
> IRR bit of the master 8259A PIC for IRQ0 to check the state of the
> output timer 0 of the PIT is no longer there. As a result, there is
> no need to use the POLL command to acknowledge the timer interrupt in
> the "8259A Virtual Wire", except for the NMI watchdog when the
> i82489DX APIC is used (this is because this particular APIC treats
> NMIs as level-triggered and keeping the input asserted would keep
> motherboard NMI sources held off for too long). Remove the unneeded
> bits and adjust comments accordingly.

applied to latest -tip, thanks Maciej!

> It seems to work for me with the NMI watchdog routed through the I/O
> APIC. The next step should move the bits from timer_interrupt() to
> nmi_watchdog_tick() where they now belong, but let's check nothing
> breaks for people first.


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