Messages in this thread | | | Date | Sat, 8 Nov 2014 23:50:39 -0800 | From | Dmitry Torokhov <> | Subject | Re: [PATCH v3 3/4] input: alps: For protocol V3, do not process data when last packet's bit7 is set |
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Hi Pali,
On Sun, Nov 02, 2014 at 12:25:09AM +0100, Pali Rohár wrote: > Sometimes on Dell Latitude laptops psmouse/alps driver receive invalid ALPS > protocol V3 packets with bit7 set in last byte. More often it can be reproduced > on Dell Latitude E6440 or E7440 with closed lid and pushing cover above touchpad. > > If bit7 in last packet byte is set then it is not valid ALPS packet. I was told > that ALPS devices never send these packets. It is not know yet who send those > packets, it could be Dell EC, bug in BIOS and also bug in touchpad firmware... > > With this patch alps driver does not process those invalid packets and drops it > with PSMOUSE_FULL_PACKET so psmouse driver does not enter to out of sync state. > > This patch fix problem when psmouse driver still resetting ALPS device when > laptop lid is closed because of receiving invalid packets in out of sync state. > > Signed-off-by: Pali Rohár <pali.rohar@gmail.com> > Tested-by: Pali Rohár <pali.rohar@gmail.com> > Cc: stable@vger.kernel.org > --- > drivers/input/mouse/alps.c | 10 ++++++++++ > 1 file changed, 10 insertions(+) > > diff --git a/drivers/input/mouse/alps.c b/drivers/input/mouse/alps.c > index 7c47e97..e802d28 100644 > --- a/drivers/input/mouse/alps.c > +++ b/drivers/input/mouse/alps.c > @@ -1181,6 +1181,16 @@ static psmouse_ret_t alps_process_byte(struct psmouse *psmouse) > return PSMOUSE_BAD_DATA; > } > > + if (priv->proto_version == ALPS_PROTO_V3 && psmouse->pktcnt == psmouse->pktsize) { > + // For protocol V3, do not process data when last packet's bit7 is set > + if (psmouse->packet[psmouse->pktcnt - 1] & 0x80) { > + psmouse_dbg(psmouse, "v3 discard packet[%i] = %x\n", > + psmouse->pktcnt - 1, > + psmouse->packet[psmouse->pktcnt - 1]); > + return PSMOUSE_FULL_PACKET; > + } > + }
I wanted to apply it, but I would like some more data. Could you please send me the dmesg with i8042.debug wit this patch in place?
Thanks!
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