Re: Intel Pentium Pro motherboard keyboard hang problem and fix
Sat, 14 Dec 1996 05:06:31 GMT

On Fri, 13 Dec 1996 19:03:03 -0800, you wrote:

> Bug Report:
> We have had reports of some models of keyboard becoming locking (no
> response to any key press) under Linux 2.0.x kernels on Intel Pentium
> Pro motherboards. Unplugging the keyboard and plugging it back in
> again resets the keyboard and fixes the problem. We have been able to
> duplicate the problem ourselves under kernels 2.0.12 and 2.0.25 with
> the Intel VS440FX and PR440FX Pentium Pro motherbaords and the
> Keytronic KB 101C Plus keyboard. The problem only occurs under Linux
> (other OSes seem fine), and appears to only occur with very specific
> motherboard and keyboard combinations.
> Fix:
> The problem appears to be related to the keyboard rate setting in
> arch/i386/boot/setup.S. If we comment-out the keybard rate setting
> code, the problem disappears:
> ! Set the keyboard repeat rate to the max
> ! mov ax,#0x0305
> ! xor bx,bx ! clear bx
> ! int 0x16
> We've started doing this. I don't have a BIOS reference handy, so I
> haven't explored changing the parameters to the int 16 call.
> Larry

It may be that this function is not supported by your BIOS.

The correct way is to call int 15/ah=C0 to see if int 16/ah=09 is supported. If
it is, then int 16/ah=09 is called to see if int 16/ax=0305 is supported. Only
then should the function be called.

Does anyone know why this call is here at all?