Messages in this thread | | | Date | Thu, 27 May 2004 16:03:32 +0200 (CEST) | From | "Maciej W. Rozycki" <> | Subject | Re: Cleanups for APIC |
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On Thu, 27 May 2004, Ingo Molnar wrote:
> > Hmm, isn't that needed to make sure the iomem writeback is completed > > before exiting the caller? > > the only thing that could happen is a POST delay in the PCI chipset - but > is that really an issue? Plus we only do the io_apic_sync() for the > masking, not the unmasking - so if it's needed then we dont do it > consistently.
The I/O APIC need not be hooked to PCI ;-) -- I'm not sure about the i82093AA, but that's definitely true for the i82489DX. The call to io_apic_sync() is needed for masking to make sure interrupts won't be dispatched after returning from the call -- this is not needed for unmasking as a delay here is harmless.
Though, now that we don't mask APIC interrupts during their service anymore the synchronization may be superfluous indeed -- other cases have to take late interrupts into account anyway.
-- + Maciej W. Rozycki, Technical University of Gdansk, Poland + +--------------------------------------------------------------+ + e-mail: macro@ds2.pg.gda.pl, PGP key available + - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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