Messages in this thread | | | Date | Tue, 08 Jan 2008 12:24:02 -0500 | From | "David P. Reed" <> | Subject | Re: [linux-kernel] Re: [PATCH] x86: provide a DMI based port 0x80 I/O delay override. |
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Windows these days does delays with timing loops or the scheduler. It doesn't use a "port". Also, Windows XP only supports machines that tend not to have timing problems that use delays. Instead, if a device takes a while to respond, it has a "busy bit" in some port or memory slot that can be tested.
Almost all of the issues in Linux where _p operations are used are (or should be) historical - IMO.
Ondrej Zary wrote: > On Tuesday 08 January 2008 02:38:15 David P. Reed wrote: > >> H. Peter Anvin wrote: >> >>> And shoot the designer of this particular microcontroller firmware. >>> >> Well, some days I want to shoot the "designer" of the entire Wintel >> architecture... it's not exactly "designed" by anybody of course, and >> today it's created largely by a collection of Taiwanese and Chinese ODM >> firms, coupled with Microsoft WinHEC and Intel folks. At least they >> follow the rules and their ACPI and BIOS code say that they are using >> port 80 very clearly if you use PnP and ACPI properly. And in the old >> days, you were "supposed" to use the system BIOS to talk to things like >> the PIT that had timing issues, not write your own code. >> > > Does anyone know what port does Windows use? I'm pretty sure that it isn't 80h > as I run Windows 98 often with port 80h debug card inserted. The last POST > code set by BIOS usually remains on the display and only changes when BIOS > does something like suspend/resume. IIRC, there was a program that was able > to display temperature from onboard sensors on the port 80h display that's > integrated on some mainboards. > >
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