Messages in this thread |  | | | Date | Tue, 1 Jan 2008 21:55:45 +0100 | | From | Christer Weinigel <> | | Subject | Re: [PATCH] x86: provide a DMI based port 0x80 I/O delay override. |
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On Tue, 01 Jan 2008 20:59:20 +0100 Rene Herman <rene.herman@keyaccess.nl> wrote:
> On 01-01-08 20:35, Christer Weinigel wrote: > > > On old hardware (or anything with an ISA bus which I'd guess > > includes the Geode SCx200 SoC which is basically a MediaGX > > processor, a southbridge and an ISA bus with a Super I/O chip on > > it) an out to 80h will use exactly one ISA cycle. > > Not to disagree with the point but more like 8 (1 us at 8 MHz). It's > the timeout property.
Ah, sorry, you're right of course.
> > I'm not sure what Alan meant with his comments about locking, but if > > changing outb_p to use an udelay means that we have to add locking, > > that is also going to affect the code size and speed. > > Explained here: > > http://lkml.org/lkml/2007/12/30/136 > > However, that's not an argument. Missing locking is a bug, and > current outb I/O delay use hiding it doesn't change that.
Thanks, I had missed that one.
Regarding Alan's comment:
>For that matter does anyone actually have video cards old enough for us >to care actually still in use with Linux today ?
I'm afraid that some PC104 systems may still use ancient video cards.
/Christer
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