lkml.org 
[lkml]   [2002]   [Jul]   [14]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: kbd not functioning in 2.5.25-dj2
On Sun, Jul 14, 2002 at 03:36:20PM +0200, Rogier Wolff wrote:

> Vojtech Pavlik wrote:
> > > > > mice: PS/2 mouse device common for all mice
> > > > > atkbd.c: Sent: f5
> > > > > atkbd.c: Received fe
> > > > > serio: i8042 KBD port at 0x60,0x64 irq 1
> [...]
> > Responses:
> >
> > 0xfe
> > Resend. Keyboard will send this if it didn't receive the last command
> > correctly.
> >
> > Unfortunately, 0xfe also happens when you send a command to a keyboard
> > that's not plugged, or when the keyboard doesn't understand the command.
> > Resending in those cases (which are the most common) would cause an
> > infinite loop ...
>
> Not if implemented correctly.
>
> Set the retry counter to 5 at the beginning.
>
> if you get 0xfe: decrement retry counter,
> if 0 :
> no keyboard connected. Give up.
> else
> Just immediately resend the last command
> else
> set the retry counter to 5 again.
> process returned code

Yes. Sure. I knew someone will suggest that. :) The only problem is,
I've never seen a keyboard sending 0xfe because it wants the command
sent again. Under normal circumstances, there aren't bit errors on the
cable.

--
Vojtech Pavlik
SuSE Labs
-
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 13:27    [W:0.094 / U:0.120 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site