Re: [PATCH] Input: ALPS - fix DualPoint flag for 74 03 28 devices

["dmitry.torokhov@gmail.com" <dmitry.torokhov@gmail.com>]

Hi,

On Thu, Nov 16, 2017 at 07:27:02AM +0000, Masaki Ota wrote:
> Hi, Pali, Aaron,
> 
> Current code is correct device setting, previous code is wrong.
> If the trackstick does not work(DUALPOINT flag disable), Device Firmware setting is wrong.
> 
> But recently I received the same report from Thinkpad L570 user, and I checked this device and found this device Firmware setting is wrong. Sorry for our mistake.
> Is your laptop L570 ?
> 
> I will add code that supports the trackstick for this device.

Sorry for resurrecting this old thread, I am just trying to understand
what went wrong here. Is the sequence of "f0 f0 e9" and "ea ea e9" is
important in getting the correct OTP data and we originally got this
order wrong? It is not clear from the original patch and discussion that
this change was intentional.

Thanks.

> 
> Best Regards,
> Masaki Ota
> -----Original Message-----
> From: Pali Rohár [mailto:pali.rohar@gmail.com] 
> Sent: Wednesday, November 15, 2017 5:35 PM
> To: 太田 真喜 Masaki Ota <masaki.ota@jp.alps.com>
> Cc: linux-input@vger.kernel.org; linux-kernel@vger.kernel.org; dmitry.torokhov@gmail.com; Aaron Ma <aaron.ma@canonical.com>
> Subject: Re: [PATCH] Input: ALPS - fix DualPoint flag for 74 03 28 devices
> 
> On Wednesday 15 November 2017 14:34:04 Aaron Ma wrote:
> > There is a regression of commit 4a646580f793 ("Input: ALPS - fix 
> > two-finger scroll breakage"), ALPS device fails with log:
> > 
> > psmouse serio1: alps: Rejected trackstick packet from non DualPoint 
> > device
> > 
> > ALPS device with id "74 03 28" report OTP[0] data 0xCE after commit 
> > 4a646580f793, after restore the OTP reading order, it becomes to 0x10 
> > as before and reports the right flag.
> > 
> > Fixes: 4a646580f793 ("Input: ALPS - fix two-finger scroll breakage")
> > Cc: <stable@vger.kernel.org>
> > Signed-off-by: Aaron Ma <aaron.ma@canonical.com>
> > ---
> >  drivers/input/mouse/alps.c | 4 ++--
> >  1 file changed, 2 insertions(+), 2 deletions(-)
> > 
> > diff --git a/drivers/input/mouse/alps.c b/drivers/input/mouse/alps.c 
> > index 579b899add26..c59b8f7ca2fc 100644
> > --- a/drivers/input/mouse/alps.c
> > +++ b/drivers/input/mouse/alps.c
> > @@ -2562,8 +2562,8 @@ static int alps_set_defaults_ss4_v2(struct 
> > psmouse *psmouse,
> >  
> >  	memset(otp, 0, sizeof(otp));
> >  
> > -	if (alps_get_otp_values_ss4_v2(psmouse, 1, &otp[1][0]) ||
> > -	    alps_get_otp_values_ss4_v2(psmouse, 0, &otp[0][0]))
> > +	if (alps_get_otp_values_ss4_v2(psmouse, 0, &otp[0][0]) ||
> > +	    alps_get_otp_values_ss4_v2(psmouse, 1, &otp[1][0]))
> >  		return -1;
> >  
> >  	alps_update_device_area_ss4_v2(otp, priv);
> 
> Masaki Ota, please look at this patch as it partially revert your commit
> 4a646580f793 ("Input: ALPS - fix two-finger scroll breakage"). Something smells here.
> 
> --
> Pali Rohár
> pali.rohar@gmail.com

-- 
Dmitry