Re: IO delay, port 0x80, and BIOS POST codes

From: Alan Cox (alan@lxorguk.ukuu.org.uk)
Date: Thu Mar 14 2002 - 17:58:16 EST


> Correct! The PCI is very much different, I'm glad, and hopefully nobody
> will be using that for deliberate waits.

On the x86 platform the PCI bridges make PCI out instructions synchronous.
Lots of driver code relies on this and people handling ports to non x86
where the odd bridge doesn't do this have had some real fun.

PCI mmio writes are however (even on the good old x86 platform) async

Alan
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/



This archive was generated by hypermail 2b29 : Fri Mar 15 2002 - 22:00:19 EST