Messages in this thread | | | Date | Sun, 30 Dec 2007 17:28:53 +0100 | From | Ingo Molnar <> | Subject | Re: [PATCH] x86: provide a DMI based port 0x80 I/O delay override |
| |
* Andi Kleen <andi@firstfloor.org> wrote:
> > > 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.
do you remember which old systems/chipsets were affected by this problem? We had many - meanwhile fixed - PIC related problems, maybe it's a red herring and the delay just papered it over.
Ingo
| |