Messages in this thread | | | Date | Sun, 30 Dec 2007 17:08:17 +0100 | From | Andi Kleen <> | Subject | Re: [PATCH] x86: provide a DMI based port 0x80 I/O delay override |
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On Sun, Dec 30, 2007 at 02:05:44PM +0100, Ingo Molnar wrote: > > * Andi Kleen <andi@firstfloor.org> wrote: > > > > drivers that then are shown to really need it could use their *own* > > > ports. > > > > The i8259 driver uses it and it is known to be needed on some old > > chipsets. But it doesn't really have any "own" ports to use afaik. > > we'll solve that via an i8259-specific quirk. That is a lot cleaner and > maintainable than the current generic, always-enabled "opt out" > port-0x80 quirk.
You mean using pci quirks + udelay? Will be probably challenging to collect PCI-IDs for that. And there might be old systems needing it without PCI. They likely won't have DMI either.
In theory you could make it a DMI year cut off of course (and assume old if no DMI, although that happens occasionally with new systems too); but that is generally considered ugly.
I don't think it's a big problem to keep delays of some form by default in 8259 -- people who care about performance should be definitely using APIC mode instead.
-Andi
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