Followup to: <a6qtb8$6fg$1@penguin.transmeta.com>
By author: torvalds@transmeta.com (Linus Torvalds)
In newsgroup: linux.dev.kernel
>
> I suspect the _real_ solution is to stop using "inb_p/outb_p" and make
> the delay explicit, although it may be that some drivers depend on the
> fact that not only is the "outb $0x80" a delay, it also tends to act as
> a posting barrier.
>
... as well as a push-out to the ISA bus. I suspect dumping the outb
way of doing it and instead wait in the CPU might cause the delay to
happen in the wrong part of the system (consider split-transaction
queued busses like HyperTransport, where a delay in the CPU doesn't
necessarily mean a delay in the southbridge.)
Port 0x80 has served us well, at least as a default. If you really
care about the POST display you can recompile using a different port.
-hpa
-- <hpa@transmeta.com> at work, <hpa@zytor.com> in private! "Unix gives you enough rope to shoot yourself in the foot." http://www.zytor.com/~hpa/puzzle.txt <amsp@zytor.com> - 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 - 22:00:18 EST