[REGRESSION] wrong coord from Thinkpad TrackPoint since 6.2 kernel

[REGRESSION] wrong coord from Thinkpad TrackPoint since 6.2 kernel

[Takashi Iwai]

Hi,

we've received a bug report about Thinkpad TrackPoint (ALPS DualPoint
Stick) on 6.2 kernel:
  https://bugzilla.opensuse.org/show_bug.cgi?id=1209805

The device reports the wrong values as the movements, e.g. sometimes a
value such as 255, 254 or -255 is returned while usually it should be
a smaller value like -1 or 2.

The evtest on 6.2.x kernel shows the wrong values like:

Event: time 1680037542.898747, type 2 (EV_REL), code 0 (REL_X), value 255
Event: time 1680037542.898747, -------------- SYN_REPORT ------------
Event: time 1680037543.145196, type 2 (EV_REL), code 0 (REL_X), value 1
Event: time 1680037543.145196, -------------- SYN_REPORT ------------
Event: time 1680037543.175087, type 2 (EV_REL), code 1 (REL_Y), value -255
Event: time 1680037543.175087, -------------- SYN_REPORT ------------
Event: time 1680037543.185421, type 2 (EV_REL), code 0 (REL_X), value 1
Event: time 1680037543.185421, type 2 (EV_REL), code 1 (REL_Y), value -255
Event: time 1680037543.185421, -------------- SYN_REPORT ------------

while 6.1.x kernel shows the correct values like:

Event: time 1680037386.318058, type 2 (EV_REL), code 0 (REL_X), value -1
Event: time 1680037386.318058, type 2 (EV_REL), code 1 (REL_Y), value -1
Event: time 1680037386.318058, -------------- SYN_REPORT ------------
Event: time 1680037386.328087, type 2 (EV_REL), code 0 (REL_X), value -1
Event: time 1680037386.328087, type 2 (EV_REL), code 1 (REL_Y), value -1
Event: time 1680037386.328087, -------------- SYN_REPORT ------------
Event: time 1680037386.338046, type 2 (EV_REL), code 0 (REL_X), value -1
Event: time 1680037386.338046, type 2 (EV_REL), code 1 (REL_Y), value -2
Event: time 1680037386.338046, -------------- SYN_REPORT ------------
  
I couldn't see any relevant changes in alps.c between those versions,
so this is likely a breakage in a lower layer.

Could you guys take a look?


Thanks!

Takashi

Re: [REGRESSION] wrong coord from Thinkpad TrackPoint since 6.2 kernel

[Hans de Goede]

Hi Takashi,

On 3/29/23 10:16, Takashi Iwai wrote:
> Hi,
> 
> we've received a bug report about Thinkpad TrackPoint (ALPS DualPoint
> Stick) on 6.2 kernel:
>   https://bugzilla.opensuse.org/show_bug.cgi?id=1209805
> 
> The device reports the wrong values as the movements, e.g. sometimes a
> value such as 255, 254 or -255 is returned while usually it should be
> a smaller value like -1 or 2.
> 
> The evtest on 6.2.x kernel shows the wrong values like:
> 
> Event: time 1680037542.898747, type 2 (EV_REL), code 0 (REL_X), value 255
> Event: time 1680037542.898747, -------------- SYN_REPORT ------------
> Event: time 1680037543.145196, type 2 (EV_REL), code 0 (REL_X), value 1
> Event: time 1680037543.145196, -------------- SYN_REPORT ------------
> Event: time 1680037543.175087, type 2 (EV_REL), code 1 (REL_Y), value -255
> Event: time 1680037543.175087, -------------- SYN_REPORT ------------
> Event: time 1680037543.185421, type 2 (EV_REL), code 0 (REL_X), value 1
> Event: time 1680037543.185421, type 2 (EV_REL), code 1 (REL_Y), value -255
> Event: time 1680037543.185421, -------------- SYN_REPORT ------------
> 
> while 6.1.x kernel shows the correct values like:
> 
> Event: time 1680037386.318058, type 2 (EV_REL), code 0 (REL_X), value -1
> Event: time 1680037386.318058, type 2 (EV_REL), code 1 (REL_Y), value -1
> Event: time 1680037386.318058, -------------- SYN_REPORT ------------
> Event: time 1680037386.328087, type 2 (EV_REL), code 0 (REL_X), value -1
> Event: time 1680037386.328087, type 2 (EV_REL), code 1 (REL_Y), value -1
> Event: time 1680037386.328087, -------------- SYN_REPORT ------------
> Event: time 1680037386.338046, type 2 (EV_REL), code 0 (REL_X), value -1
> Event: time 1680037386.338046, type 2 (EV_REL), code 1 (REL_Y), value -2
> Event: time 1680037386.338046, -------------- SYN_REPORT ------------
>   
> I couldn't see any relevant changes in alps.c between those versions,
> so this is likely a breakage in a lower layer.
> 
> Could you guys take a look?

I believe this is caused by the kernel now using -funsigned-char
everywhere and this should be fixed by this commit:

https://git.kernel.org/pub/scm/linux/kernel/git/dtor/input.git/commit/?h=for-linus&id=754ff5060daf5a1cf4474eff9b4edeb6c17ef7ab

And there is a similar issue in the focaltech touchpad driver:

https://git.kernel.org/pub/scm/linux/kernel/git/dtor/input.git/commit/?h=for-linus&id=8980f190947ba29f23110408e712444884b74251

Dmitry, since this is hitting 6.2 users, perhaps you can send
a pull-req for your current for-linus branch to get the fix
on its way to stable ?

Regards,

Hans

Re: [REGRESSION] wrong coord from Thinkpad TrackPoint since 6.2 kernel

[Takashi Iwai]

On Wed, 29 Mar 2023 11:22:18 +0200,
Hans de Goede wrote:
> 
> Hi Takashi,
> 
> On 3/29/23 10:16, Takashi Iwai wrote:
> > Hi,
> > 
> > we've received a bug report about Thinkpad TrackPoint (ALPS DualPoint
> > Stick) on 6.2 kernel:
> >   https://bugzilla.opensuse.org/show_bug.cgi?id=1209805
> > 
> > The device reports the wrong values as the movements, e.g. sometimes a
> > value such as 255, 254 or -255 is returned while usually it should be
> > a smaller value like -1 or 2.
> > 
> > The evtest on 6.2.x kernel shows the wrong values like:
> > 
> > Event: time 1680037542.898747, type 2 (EV_REL), code 0 (REL_X), value 255
> > Event: time 1680037542.898747, -------------- SYN_REPORT ------------
> > Event: time 1680037543.145196, type 2 (EV_REL), code 0 (REL_X), value 1
> > Event: time 1680037543.145196, -------------- SYN_REPORT ------------
> > Event: time 1680037543.175087, type 2 (EV_REL), code 1 (REL_Y), value -255
> > Event: time 1680037543.175087, -------------- SYN_REPORT ------------
> > Event: time 1680037543.185421, type 2 (EV_REL), code 0 (REL_X), value 1
> > Event: time 1680037543.185421, type 2 (EV_REL), code 1 (REL_Y), value -255
> > Event: time 1680037543.185421, -------------- SYN_REPORT ------------
> > 
> > while 6.1.x kernel shows the correct values like:
> > 
> > Event: time 1680037386.318058, type 2 (EV_REL), code 0 (REL_X), value -1
> > Event: time 1680037386.318058, type 2 (EV_REL), code 1 (REL_Y), value -1
> > Event: time 1680037386.318058, -------------- SYN_REPORT ------------
> > Event: time 1680037386.328087, type 2 (EV_REL), code 0 (REL_X), value -1
> > Event: time 1680037386.328087, type 2 (EV_REL), code 1 (REL_Y), value -1
> > Event: time 1680037386.328087, -------------- SYN_REPORT ------------
> > Event: time 1680037386.338046, type 2 (EV_REL), code 0 (REL_X), value -1
> > Event: time 1680037386.338046, type 2 (EV_REL), code 1 (REL_Y), value -2
> > Event: time 1680037386.338046, -------------- SYN_REPORT ------------
> >   
> > I couldn't see any relevant changes in alps.c between those versions,
> > so this is likely a breakage in a lower layer.
> > 
> > Could you guys take a look?
> 
> I believe this is caused by the kernel now using -funsigned-char
> everywhere and this should be fixed by this commit:
> 
> https://git.kernel.org/pub/scm/linux/kernel/git/dtor/input.git/commit/?h=for-linus&id=754ff5060daf5a1cf4474eff9b4edeb6c17ef7ab

Ah, that makes sense!

I'll build a test kernel with this fix and ask the reporter for
testing.

> And there is a similar issue in the focaltech touchpad driver:
> 
> https://git.kernel.org/pub/scm/linux/kernel/git/dtor/input.git/commit/?h=for-linus&id=8980f190947ba29f23110408e712444884b74251
> 
> Dmitry, since this is hitting 6.2 users, perhaps you can send
> a pull-req for your current for-linus branch to get the fix
> on its way to stable ?

That'll be great.


Thanks!

Takashi

Re: [REGRESSION] wrong coord from Thinkpad TrackPoint since 6.2 kernel

[Takashi Iwai]

On Wed, 29 Mar 2023 11:28:53 +0200,
Takashi Iwai wrote:
> 
> On Wed, 29 Mar 2023 11:22:18 +0200,
> Hans de Goede wrote:
> > 
> > Hi Takashi,
> > 
> > On 3/29/23 10:16, Takashi Iwai wrote:
> > > Hi,
> > > 
> > > we've received a bug report about Thinkpad TrackPoint (ALPS DualPoint
> > > Stick) on 6.2 kernel:
> > >   https://bugzilla.opensuse.org/show_bug.cgi?id=1209805
> > > 
> > > The device reports the wrong values as the movements, e.g. sometimes a
> > > value such as 255, 254 or -255 is returned while usually it should be
> > > a smaller value like -1 or 2.
> > > 
> > > The evtest on 6.2.x kernel shows the wrong values like:
> > > 
> > > Event: time 1680037542.898747, type 2 (EV_REL), code 0 (REL_X), value 255
> > > Event: time 1680037542.898747, -------------- SYN_REPORT ------------
> > > Event: time 1680037543.145196, type 2 (EV_REL), code 0 (REL_X), value 1
> > > Event: time 1680037543.145196, -------------- SYN_REPORT ------------
> > > Event: time 1680037543.175087, type 2 (EV_REL), code 1 (REL_Y), value -255
> > > Event: time 1680037543.175087, -------------- SYN_REPORT ------------
> > > Event: time 1680037543.185421, type 2 (EV_REL), code 0 (REL_X), value 1
> > > Event: time 1680037543.185421, type 2 (EV_REL), code 1 (REL_Y), value -255
> > > Event: time 1680037543.185421, -------------- SYN_REPORT ------------
> > > 
> > > while 6.1.x kernel shows the correct values like:
> > > 
> > > Event: time 1680037386.318058, type 2 (EV_REL), code 0 (REL_X), value -1
> > > Event: time 1680037386.318058, type 2 (EV_REL), code 1 (REL_Y), value -1
> > > Event: time 1680037386.318058, -------------- SYN_REPORT ------------
> > > Event: time 1680037386.328087, type 2 (EV_REL), code 0 (REL_X), value -1
> > > Event: time 1680037386.328087, type 2 (EV_REL), code 1 (REL_Y), value -1
> > > Event: time 1680037386.328087, -------------- SYN_REPORT ------------
> > > Event: time 1680037386.338046, type 2 (EV_REL), code 0 (REL_X), value -1
> > > Event: time 1680037386.338046, type 2 (EV_REL), code 1 (REL_Y), value -2
> > > Event: time 1680037386.338046, -------------- SYN_REPORT ------------
> > >   
> > > I couldn't see any relevant changes in alps.c between those versions,
> > > so this is likely a breakage in a lower layer.
> > > 
> > > Could you guys take a look?
> > 
> > I believe this is caused by the kernel now using -funsigned-char
> > everywhere and this should be fixed by this commit:
> > 
> > https://git.kernel.org/pub/scm/linux/kernel/git/dtor/input.git/commit/?h=for-linus&id=754ff5060daf5a1cf4474eff9b4edeb6c17ef7ab
> 
> Ah, that makes sense!
> 
> I'll build a test kernel with this fix and ask the reporter for
> testing.

And it's confirmed that the commit above fixes the problem indeed.


thanks,

Takashi

Re: [REGRESSION] wrong coord from Thinkpad TrackPoint since 6.2 kernel

[Linux regression tracking (Thorsten Leemhuis)]

On 29.03.23 11:22, Hans de Goede wrote:
> On 3/29/23 10:16, Takashi Iwai wrote:
>> we've received a bug report about Thinkpad TrackPoint (ALPS DualPoint
>> Stick) on 6.2 kernel:
>>   https://bugzilla.opensuse.org/show_bug.cgi?id=1209805
>
> [...]
> 
> I believe this is caused by the kernel now using -funsigned-char
> everywhere and this should be fixed by this commit:
> 
> https://git.kernel.org/pub/scm/linux/kernel/git/dtor/input.git/commit/?h=for-linus&id=754ff5060daf5a1cf4474eff9b4edeb6c17ef7ab
> 
> And there is a similar issue in the focaltech touchpad driver:
> 
> https://git.kernel.org/pub/scm/linux/kernel/git/dtor/input.git/commit/?h=for-linus&id=8980f190947ba29f23110408e712444884b74251
> 
> Dmitry, since this is hitting 6.2 users, perhaps you can send
> a pull-req for your current for-linus branch to get the fix
> on its way to stable ?

Hmm, no reply from Dmitry here or any other mail from him on lore since
a week. No big deal, but nevertheless a bit unfortunate, as I totally
agree: it would be really good to get this regressions fixed rather
sooner than later.

Is there any in-official de-facto co-maintainer for input that could
help out? CCing Jonathan, who according to get_maintainer.pl regularly
contributes to the input subsystem.

Guess if nothing happens soon I'll ask Linus to merge those two changes
directly, maybe he'll take them.

Ciao, Thorsten

Re: [REGRESSION] wrong coord from Thinkpad TrackPoint since 6.2 kernel

[Dmitry Torokhov]

On Thu, Mar 30, 2023 at 10:23:49AM +0200, Takashi Iwai wrote:
> On Wed, 29 Mar 2023 11:28:53 +0200,
> Takashi Iwai wrote:
> > 
> > On Wed, 29 Mar 2023 11:22:18 +0200,
> > Hans de Goede wrote:
> > > 
> > > Hi Takashi,
> > > 
> > > On 3/29/23 10:16, Takashi Iwai wrote:
> > > > Hi,
> > > > 
> > > > we've received a bug report about Thinkpad TrackPoint (ALPS DualPoint
> > > > Stick) on 6.2 kernel:
> > > >   https://bugzilla.opensuse.org/show_bug.cgi?id=1209805
> > > > 
> > > > The device reports the wrong values as the movements, e.g. sometimes a
> > > > value such as 255, 254 or -255 is returned while usually it should be
> > > > a smaller value like -1 or 2.
> > > > 
> > > > The evtest on 6.2.x kernel shows the wrong values like:
> > > > 
> > > > Event: time 1680037542.898747, type 2 (EV_REL), code 0 (REL_X), value 255
> > > > Event: time 1680037542.898747, -------------- SYN_REPORT ------------
> > > > Event: time 1680037543.145196, type 2 (EV_REL), code 0 (REL_X), value 1
> > > > Event: time 1680037543.145196, -------------- SYN_REPORT ------------
> > > > Event: time 1680037543.175087, type 2 (EV_REL), code 1 (REL_Y), value -255
> > > > Event: time 1680037543.175087, -------------- SYN_REPORT ------------
> > > > Event: time 1680037543.185421, type 2 (EV_REL), code 0 (REL_X), value 1
> > > > Event: time 1680037543.185421, type 2 (EV_REL), code 1 (REL_Y), value -255
> > > > Event: time 1680037543.185421, -------------- SYN_REPORT ------------
> > > > 
> > > > while 6.1.x kernel shows the correct values like:
> > > > 
> > > > Event: time 1680037386.318058, type 2 (EV_REL), code 0 (REL_X), value -1
> > > > Event: time 1680037386.318058, type 2 (EV_REL), code 1 (REL_Y), value -1
> > > > Event: time 1680037386.318058, -------------- SYN_REPORT ------------
> > > > Event: time 1680037386.328087, type 2 (EV_REL), code 0 (REL_X), value -1
> > > > Event: time 1680037386.328087, type 2 (EV_REL), code 1 (REL_Y), value -1
> > > > Event: time 1680037386.328087, -------------- SYN_REPORT ------------
> > > > Event: time 1680037386.338046, type 2 (EV_REL), code 0 (REL_X), value -1
> > > > Event: time 1680037386.338046, type 2 (EV_REL), code 1 (REL_Y), value -2
> > > > Event: time 1680037386.338046, -------------- SYN_REPORT ------------
> > > >   
> > > > I couldn't see any relevant changes in alps.c between those versions,
> > > > so this is likely a breakage in a lower layer.
> > > > 
> > > > Could you guys take a look?
> > > 
> > > I believe this is caused by the kernel now using -funsigned-char
> > > everywhere and this should be fixed by this commit:
> > > 
> > > https://git.kernel.org/pub/scm/linux/kernel/git/dtor/input.git/commit/?h=for-linus&id=754ff5060daf5a1cf4474eff9b4edeb6c17ef7ab
> > 
> > Ah, that makes sense!
> > 
> > I'll build a test kernel with this fix and ask the reporter for
> > testing.
> 
> And it's confirmed that the commit above fixes the problem indeed.

Sorry for sitting on this, I just sent a pull request and it was merged.

Thanks.

-- 
Dmitry