Re: [PATCH 0/3] Boot IRQ quirks for Broadcom and AMD/ATI

From: Ingo Molnar
Date: Sun Jul 13 2008 - 17:02:02 EST



* Olaf Dabrunz <od@xxxxxxx> wrote:

> This is against linux-2.6-tip, branch pci-ioapic-boot-irq-quirks.
>
> The corrected versions of the Broadcom and AMD/ATI boot IRQ quirks,
> and a patch that uses DECLARE_PCI_FIXUP_FINAL instead of *_EARLY, and
> adds *_RESUME.
>
> The AMD/ATI SB700S does not need a quirk. The boot IRQs here are
> active even when the IO-APIC lines are not masked. So even for
> traditional IRQ handling that does not use masking, the boot IRQs need
> to be disabled by the BIOS. If there are actual cases of BIOSes that
> do not disable these boot IRQs in APIC mode, we could consider
> including an SB700S patch. But I doubt this will be needed, as this
> problem would quickly surface during testing with any general-purpose
> OS.
>
> The quirk for the AMD 8131 and AMD 8132 takes identical action as an
> existing quirk for the AMD 8131 rev. A0 and B0. The existing quirk is
> due to an AMD erratum to fix IO-APIC mode. Our patch now deletes the
> older quirk and adds a comment to the new one that describes the two
> purposes of the quirk.

applied to tip/x86/pci-ioapic-boot-irq-quirks, thanks Olaf.

Jesse, what do you think about this topic? We are keeping it separate
for the time being. They are not particularly pretty, but being able to
mask/unmask irqs (without generating those legacy IRQs and creating an
IRQ storm) is essential to -rt.

Ingo
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