Re: [PATCH] Fix ALPS sync loss

[Vojtech Pavlik <vojtech@suse.cz>]

On Tue, Feb 08, 2005 at 06:40:12PM -0500, Dmitry Torokhov wrote:
> Hi,
> 
> Here is the promised patch. It turns out protocol validation code was
> a bit (or rather a byte ;) ) off.
> 
> Please let me know if it fixes your touchpad and I believe it would be
> nice to have it in 2.6.11.

Yes, I can't reproduce sync losses that were possible to create with
simultaneous use of the pad anf the touchpoint. Patch applied.

> 
> ===================================================================
> 
> 
> ChangeSet@1.2147, 2005-02-08 18:12:06-05:00, dtor_core@ameritech.net
>   Input: alps - fix protocol validation rules causing touchpad
>          to lose sync if an absolute packet is received after
>          a relative packet with negative Y displacement.
>   
>   Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
>   
> 
> 
>  alps.c |    4 ++--
>  1 files changed, 2 insertions(+), 2 deletions(-)
> 
> 
> ===================================================================
> 
> 
> 
> diff -Nru a/drivers/input/mouse/alps.c b/drivers/input/mouse/alps.c
> --- a/drivers/input/mouse/alps.c	2005-02-08 18:16:27 -05:00
> +++ b/drivers/input/mouse/alps.c	2005-02-08 18:16:27 -05:00
> @@ -198,8 +198,8 @@
>  		return PSMOUSE_BAD_DATA;
>  
>  	/* Bytes 2 - 6 should have 0 in the highest bit */
> -	if (psmouse->pktcnt > 1 && psmouse->pktcnt <= 6 &&
> -	    (psmouse->packet[psmouse->pktcnt] & 0x80))
> +	if (psmouse->pktcnt >= 2 && psmouse->pktcnt <= 6 &&
> +	    (psmouse->packet[psmouse->pktcnt - 1] & 0x80))
>  		return PSMOUSE_BAD_DATA;
>  
>  	if (psmouse->pktcnt == 6) {
> 

-- 
Vojtech Pavlik
SuSE Labs, SuSE CR