Bug 217182

Summary: Dell Latitude E7450 Trackpoint not working as expected
Product: Drivers Reporter: Steffen (wiesenbergsteffen+lxkernel)
Component: Input DevicesAssignee: drivers_input-devices
Status: RESOLVED CODE_FIX    
Severity: normal CC: alan.christopher.jenkins, lanelone, regressions
Priority: P1    
Hardware: Intel   
OS: Linux   
Kernel Version: 6.2.x Subsystem:
Regression: No Bisected commit-id:
Attachments: dmesg output 6.1.14 (working)
dmesg output 6.2.2 (broken)
dmesg output 6.2.6 (broken)

Description Steffen 2023-03-12 11:17:02 UTC
Hi,
I'm new to this bug tracking system and just a user, not a developer.

I use a Dell Latitude E7450 running with the Debian unstable based distribution Siduction. 
After upgrading to Linux kernel 6.2.x the Trackpoint does not work anymore as expected. It uses an Alps PS/2 DualPoint Stick.
Even slight touches in any direction send the cursor to the top right corner of the screen where it stays regardless of actual pointer movement. This also appears in console mode. One can retrieve the pointer again with the touchpad, but I'm more precise with the Trackpoint and prefer using that.
The Trackpoint works well in kernel 6.1.14
Can somebody help?
Comment 1 The Linux kernel's regression tracker (Thorsten Leemhuis) 2023-03-13 08:55:26 UTC
Can you please attach the dmesg output from a working kernel and a broken one (ideally a really fresh one like 6.2.5)
Comment 2 Steffen 2023-03-13 09:19:42 UTC
Created attachment 303934 [details]
dmesg output 6.1.14 (working)

This is the dmesg output of the working kernel 6.1.14.
Comment 3 Steffen 2023-03-13 09:21:04 UTC
Created attachment 303935 [details]
dmesg output 6.2.2 (broken)

This is the dmesg output of the broken kernel 6.2.2.
Comment 4 Steffen 2023-03-13 09:22:29 UTC
Thanks for reply, I have attached the files above. 
The kernel 6.2.5 has not yet been packaged by my distribution.
Comment 5 Steffen 2023-03-14 06:00:14 UTC
Created attachment 303944 [details]
dmesg output 6.2.6 (broken)

Updated dmesg output for kernel version 6.2.6.
Comment 6 Radek 2023-03-14 08:00:31 UTC
I am experiencing the same issue with kernel >6.2.x on Toshiba Z30 with Alps PS/2 DualPoint trackpoint / touchpad. The cursor jumps top right even with the lowest sensitivity settings. It works just fine with 6.1 or lower.
Comment 7 Steffen 2023-03-14 17:20:53 UTC
If it helps:
The issue is NOT present for folowing models: Latitude E6430, E7440, 5411, Precision M4700, M4800.
Comment 8 The Linux kernel's regression tracker (Thorsten Leemhuis) 2023-03-18 17:29:04 UTC
There is a similar looking report here:
https://gitlab.freedesktop.org/libinput/libinput/-/issues/871#note_1829296

And a potential fix for it:
https://lore.kernel.org/linux-input/20230318144206.14309-1-msizanoen@qtmlabs.xyz/
Comment 9 The Linux kernel's regression tracker (Thorsten Leemhuis) 2023-03-20 05:45:43 UTC
(In reply to The Linux kernel's regression tracker (Thorsten Leemhuis) from comment #8)

> And a potential fix for it:
> https://lore.kernel.org/linux-input/20230318144206.14309-1-msizanoen@qtmlabs.
> xyz/

A updated patch can be found here:

https://lore.kernel.org/linux-input/20230320045228.182259-1-msizanoen@qtmlabs.xyz/
Comment 10 wiesenbergsteffen 2023-03-24 06:11:16 UTC
Hi Thorsten,

looks promising from an users perspective that a patch is available. Any 
clue when this patch will be merged to current kernels? Looks like it is 
not yet present in 6.2.8.

Cheers,
Steffen

On 20.03.2023 06:45, bugzilla-daemon@kernel.org wrote:
> https://bugzilla.kernel.org/show_bug.cgi?id=217182
> 
> --- Comment #9 from The Linux kernel's regression tracker (Thorsten Leemhuis)
> (regressions@leemhuis.info) ---
> (In reply to The Linux kernel's regression tracker (Thorsten Leemhuis) from
> comment #8)
> 
>> And a potential fix for it:
>>
>> https://lore.kernel.org/linux-input/20230318144206.14309-1-msizanoen@qtmlabs.
>> xyz/
> 
> A updated patch can be found here:
> 
>
> https://lore.kernel.org/linux-input/20230320045228.182259-1-msizanoen@qtmlabs.xyz/
>
Comment 11 The Linux kernel's regression tracker (Thorsten Leemhuis) 2023-03-24 09:42:25 UTC
(In reply to wiesenbergsteffen from comment #10)
> looks promising from an users perspective that a patch is available.

Well, would be good if someone could check if this patch really helps in this case.

> Any clue when this patch will be merged to current kernels?

Likely within one week after it was mainlined, but I have no idea when the latter happen; maybe still this week, maybe next.
Comment 12 Radek 2023-03-30 06:22:11 UTC
I used v3 of the patch mentioned in this thread against latest vanilla 6.2.8 kernel. It works well with Alps DualPoint stick on Toshiba Z30. Explicit casting of variables solved the issue.
Comment 13 Steffen 2023-08-17 14:27:51 UTC
Dear all,
sorry for the long delay, but days before the patch arrived in main line kernel, my device died and I could not test this anymore. I could also not get my hands on a spare device of the same model until now.
But now with kernel 6.4.10 already I can confirm (with a spare device) that the problem is solved for Latitude E7450.
I will mark the status as resolved. 
Thanks to everyone involved.