Re: Keyboard regression by intel-vbtn

[Takashi Iwai <tiwai@suse.de>]

On Tue, 29 Sep 2020 11:21:27 +0200,
Hans de Goede wrote:
> 
> Hi,
> 
> On 9/29/20 10:48 AM, Takashi Iwai wrote:
> > Hi Hans,
> >
> > it seems that the recent update of intel-vtn broke the keyboard input
> > on some laptops with libinput:
> >    https://bugzilla.opensuse.org/show_bug.cgi?id=1175599
> >
> > Blacklisting intel-vtn fixes the issue, so it's likely the falsely
> > reported tablet mode switch that leads libinput misbehaving.  The
> > affected machines are Acer E5-511 and ASUS X756UX laptops, and they
> > shouldn't have the tablet mode at all, AFAIK.
> >
> > Could you take a look?  I guess it's the commit cfae58ed681c that
> > broke.  The chassis type is Notebook on those, and this type should be
> > excluded as well as Laptop.
> >
> > The dmidecode outputs and other info are found in the bugzilla above:
> >    https://bugzilla.opensuse.org/attachment.cgi?id=841999
> >    https://bugzilla.opensuse.org/attachment.cgi?id=842039
> >
> > The one for ASUS is embedded in hwinfo outpt:
> >    https://bugzilla.opensuse.org/attachment.cgi?id=841157
> 
> Ugh. What a mess, sorry about this.
> 
> So as the commit message from commit cfae58ed681c
> ("platform/x86: intel-vbtn: Only blacklist SW_TABLET_MODE on the 9 / "Laptop" chasis-type")
> explains the reason to NOT NOT report SW_TABLET_MODE on devices
> with a chassis type of 10 ("Notebook") is that at least
> some HP ... 360 ... models use that chassis type and do
> report a correct SW_TABLET_MODE through the intel-vbtn driver.
> 
> The SW_TABLET_MODE on these actually got regressed by
> de9647efeaa9 ("platform/x86: intel-vbtn: Only activate tablet mode switch on 2-in-1's")
> which first introduced the chassis-type check.
> 
> And to complicate things further even though some
> HP ... 360 ... models use that chassis type and from the DSDT
> it seems that they do report a correct SW_TABLET_MODE through the
> intel-vbtn driver. In practice it is also broken on some
> HP ... 360 ... models, see:
> 
> https://forum.manjaro.org/t/keyboard-and-touchpad-only-work-on-kernel-5-6/22668
> http://git.infradead.org/linux-platform-drivers-x86.git/commit/d823346876a970522ff9e4d2b323c9b734dcc4de
> "platform/x86: intel-vbtn: Fix SW_TABLET_MODE always reporting 1 on the HP Pavilion 11 x360"

Oohoo, what a wonderful world :)

> Since the problem of wrongly reporting SW_TABLET_MODE=1 in combination
> with libinput, leads to a non-usable system. Where as OTOH many people will
> not even notice when SW_TABLET_MODE is not being reported, I believe it
> is best to move to a dmi based allow-list approach here, as we recently
> did for SW_TABLET_MODE reporting by the asus-wmi driver. Allowing:
> 
> dmi chassis-types: 8 /* Portable */,  31 /* Convertible */, 32 /* Detachable */
> and the HP Stream x360 11-p000nd which has working intel-vbtn SW_TABLET_MODE
> support combined with a chassis-type of 10 /* Notebook */.
> 
> I will prepare a patch for this right away.

Great, thanks!  I'll build a test kernel when receiving a patch soon.


Takashi

> Note this patch will effectively replace:
> "platform/x86: intel-vbtn: Fix SW_TABLET_MODE always reporting 1 on the HP Pavilion 11 x360"
> We will no longer need this workaround with the allow list and I believe
> that it would be better to drop that one.
> 
> Andy can you drop that one from your review-andy branch please?
> 
> Regards,
> 
> Hans
> 
>