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Date:   Fri, 18 Mar 2022 14:11:39 +0100
Message-ID: <s5hlex72yno.wl-tiwai@suse.de>
From:   Takashi Iwai <tiwai@suse.de>
To:     =?UTF-8?B?Sm9zw6kgRXhww7NzaXRv?= <jose.exposito89@gmail.com>
Cc:     Takashi Iwai <tiwai@suse.de>, linux-input@vger.kernel.org,
        Peter Hutterer <peter.hutterer@who-t.net>,
        Benjamin Tissoires <benjamin.tissoires@redhat.com>,
        Jiri Kosina <jkosina@suse.cz>, stable@vger.kernel.org,
        regressions@lists.linux.dev, linux-kernel@vger.kernel.org
Subject: Re: [REGRESSION] Right touchpad button disabled on Dell 7750
In-Reply-To: <20220318130740.GA33535@elementary>
References: <s5htubv32s8.wl-tiwai@suse.de>
        <20220318130740.GA33535@elementary>
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On Fri, 18 Mar 2022 14:07:40 +0100,
José Expósito wrote:
> 
> Hi Takashi,
> 
> Thanks for reporting the regression here.
> 
> On Fri, Mar 18, 2022 at 12:42:31PM +0100, 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?
> 
> A couple of days ago another user with the same laptop (Dell Precision
> 7550 or 7750) emailed me to report the issue and I sent him a patch for
> testing.
> 
> I he confirms that the patch works, I'll send it to the mailing list.
> 
> I believe that your analysis of the regression is correct and I think
> that we'd need to add a quirk for the device.
> 
> In case you want to have a look to the patch, I added it to this
> libinput [1] report.

Great, I'll try to build and ask the reporter to test with the patch.

Thanks!


Takashi
> 
> Thanks,
> Jose
> 
> [1] https://gitlab.freedesktop.org/libinput/libinput/-/merge_requests/726#note_1303623
>