Re: [REGRESSION] Right touchpad button disabled on Dell 7750 #forregzbot

[Thorsten Leemhuis <regressions@leemhuis.info>]

TWIMC: this mail is primarily send for documentation purposes and for
regzbot, my Linux kernel regression tracking bot. These mails usually
contain '#forregzbot' in the subject, to make them easy to spot and filter.

Hi, this is your Linux kernel regression tracker. Top-posting for once,
to make this easily accessible to everyone.

Seems below regression soon will be getting fixed, but with the nearing
final I want to have this in the tracking to make sure everyone is aware
of it:

#regzbot ^introduced 37ef4c19b4c659926ce65
#regzbot title HID: multitouch: right touchpad button is disabled on
recent kernels
#regzbot ignore-activity
#regzbot link:
https://gitlab.freedesktop.org/libinput/libinput/-/merge_requests/726#note_1303623

Ciao, Thorsten (wearing his 'the Linux kernel's regression tracker' hat)

P.S.: As the Linux kernel's regression tracker I'm getting a lot of
reports on my table. I can only look briefly into most of them and lack
knowledge about most of the areas they concern. I thus unfortunately
will sometimes get things wrong or miss something important. I hope
that's not the case here; if you think it is, don't hesitate to tell me
in a public reply, it's in everyone's interest to set the public record
straight.

On 18.03.22 12:42, Takashi Iwai wrote:
> Hi,
> 
> we received a bug report about the regression of the touchpad on Dell
> 7750 laptop, the right touchpad button is disabled on recent kernels:
>   https://bugzilla.suse.com/show_bug.cgi?id=1197243
> 
> Note that it's a physical button, not a virtual clickpad button.
> 
> The regression seems introduced by the upstream commit
> 37ef4c19b4c659926ce65a7ac709ceaefb211c40 ("Input: clear
> BTN_RIGHT/MIDDLE on buttonpads") that was backported to stable 5.16.x
> kernel.
> 
> The device is managed by hid-multitouch driver, and the further
> investigation revealed that it's rather an incorrectly recognized
> buttonpad property; namely, ID_DG_BUTTONTYPE reports it being 0 =
> clickable touchpad although it's not.  I built a test kernel to ignore
> this check and it was confirmed to make the right button working again
> by the reporter.
> 
> Is this check really correct in general?  Or do we need some
> device-specific quirk?
> 
> 
> thanks,
> 
> Takashi
> 
>