linux-kernel - Re: [PATCH v3] hid/hid-multitouch: Keep latency normal on deactivate for reactivation gesture

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <rejkk25fhay4ozlnrior3vbpo4wa6s2rpezmt3kydf7e3jr7k4@vv7423v4mssq>
Date: Fri, 19 Dec 2025 14:10:17 +0100
From: Benjamin Tissoires <bentiss@...nel.org>
To: Werner Sembach <wse@...edocomputers.com>
Cc: Jiri Kosina <jikos@...nel.org>, linux-input@...r.kernel.org, 
	linux-kernel@...r.kernel.org
Subject: Re: [PATCH v3] hid/hid-multitouch: Keep latency normal on deactivate
 for reactivation gesture

On Nov 12 2025, Werner Sembach wrote:
> 
> Am 12.11.25 um 15:47 schrieb Werner Sembach:
> > Uniwill devices have a built in gesture in the touchpad to de- and
> > reactivate it by double taping the upper left corner. This gesture stops
> > working when latency is set to high, so this patch keeps the latency on
> > normal.
> > 
> > Signed-off-by: Werner Sembach <wse@...edocomputers.com>
> > Cc: stable@...r.kernel.org
> > ---
> > V1->V2: Use a quirk to narrow down the devices this is applied to.
> > V2->V3: Fix this patch breaking touchpads on some devices.
> >          Add another device ID.
> > 
> > I have three Uniwill devices at hand right now that have at least two
> > physically different touchpads, but same Vendor + Product ID combination.
> > Maybe the vendor uses this product ID for all i2c connected touchpads, or
> > it is used as some kind of subvendor ID to indicate Uniwill?
> > 
> > To be able to really narrow it down to Uniwill only devices I would need to
> > check DMI strings, but then I will probably narrow it down to much as I
> > only know what we at TUXEDO use there.
> > 
> >   drivers/hid/hid-multitouch.c | 26 +++++++++++++++++++++++++-
> >   1 file changed, 25 insertions(+), 1 deletion(-)
> > 
> > diff --git a/drivers/hid/hid-multitouch.c b/drivers/hid/hid-multitouch.c
> > index 179dc316b4b51..ed9eb4e0d5038 100644
> > --- a/drivers/hid/hid-multitouch.c
> > +++ b/drivers/hid/hid-multitouch.c
> > @@ -76,6 +76,7 @@ MODULE_LICENSE("GPL");
> >   #define MT_QUIRK_DISABLE_WAKEUP		BIT(21)
> >   #define MT_QUIRK_ORIENTATION_INVERT	BIT(22)
> >   #define MT_QUIRK_APPLE_TOUCHBAR		BIT(23)
> > +#define MT_QUIRK_KEEP_LATENCY_ON_CLOSE	BIT(24)
> >   #define MT_INPUTMODE_TOUCHSCREEN	0x02
> >   #define MT_INPUTMODE_TOUCHPAD		0x03
> > @@ -211,6 +212,7 @@ static void mt_post_parse(struct mt_device *td, struct mt_application *app);
> >   #define MT_CLS_WIN_8_DISABLE_WAKEUP		0x0016
> >   #define MT_CLS_WIN_8_NO_STICKY_FINGERS		0x0017
> >   #define MT_CLS_WIN_8_FORCE_MULTI_INPUT_NSMU	0x0018
> > +#define MT_CLS_WIN_8_KEEP_LATENCY_ON_CLOSE	0x0019
> A college realized that at some points in the code some, but not all, of the
> MT_CLS_WIN_8* classes are checked for directly. Should I add my new class
> there too?

It depends. If it's truely a WIN_8 touchpad then I guess those checks
are here for a reason, but if this particular device works without them,
then it's your call in the end.

Cheers,
Benjamin