Messages in this thread | | | Date | Fri, 7 Dec 2007 17:19:57 +0000 | From | Alan Cox <> | Subject | Re: RFC: outb 0x80 in inb_p, outb_p harmful on some modern AMD64 with MCP51 laptops |
| |
On Fri, 7 Dec 2007 17:31:16 +0100 Andi Kleen <andi@firstfloor.org> wrote:
> > You don't need to. Port 0x80 historically is about 8uS so just udelay(8) > > and make sure the initial default delay is conservative enough before the > > How would you make it conservative enough handling let's say a 6Ghz CPU > that can execute multiple jumps per cycle?
Pick a sane worst case and go with it at boot. We don't have to be accurate before we tune udelay - over long in uSecs isnt going to hurt, and most post boot _p's can be replaced by udelay(8) now
Alan
| |