Re: [PATCH] Fix ALPS sync loss

[Joseph Pingenot <trelane@digitasaru.net>]

>From Dmitry Torokhov on Tuesday, 08 February, 2005:
>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.

This patch seems to be working for me too.  Thanks a million, Dmitry!
  I owe you a beer some time.  :)

-Joseph

>===================================================================
>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) {

-- 
Joseph===============================================trelane@digitasaru.net
      Graduate Student in Physics, Freelance Free Software Developer