On Mon, Jul 28, 2003 at 05:43:51PM +0200, Maciej W. Rozycki wrote:
> On Mon, 28 Jul 2003, Andries Brouwer wrote:
>
> > > Well, are timeouts needed at all?
> >
> > Yes. We send a command to the keyboard. It may react, or it may not.
>
> But we need not wait for that actively. If we are unsure about a result
> of a command, then we may send a command in question followed with an echo
> request. This assures an IRQ will finally arrive and if no command
> response arrives before an echo response, then the keyboard ignored the
> command. I used this approach many years ago to differ between PS/2
> keyboards (which respond with 0xfa,0xab,0x83 to a request for ID) and
> genuine PC/AT ones (which respond with lone 0xfa). It worked.
And what did you do for XT? :-)
-
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 : Thu Jul 31 2003 - 22:00:36 EST