lkml.org 
[lkml]   [2003]   [Jul]   [28]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: i8042 problem
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/

\
 
 \ /
  Last update: 2005-03-22 13:47    [from the cache]
©2003-2011 Jasper Spaans