linux-kernel - Re: Dell Vostro 3360 multimedia keys

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Date:   Sat, 27 Jan 2018 15:05:57 +0100
From:   Pali Rohár <pali.rohar@...il.com>
To:     Oleksandr Natalenko <oleksandr@...alenko.name>
Cc:     Mario Limonciello <mario_limonciello@...l.com>,
        platform-driver-x86@...r.kernel.org, linux-kernel@...r.kernel.org,
        Matthew Garrett <mjg59@...f.ucam.org>,
        Darren Hart <dvhart@...radead.org>,
        Andy Shevchenko <andy@...radead.org>,
        Dmitry Torokhov <dmitry.torokhov@...il.com>
Subject: Re: Dell Vostro 3360 multimedia keys

On Tuesday 21 November 2017 19:58:24 Oleksandr Natalenko wrote:
> Hi.
> 
> On úterý 21. listopadu 2017 19:36:24 CET Pali Rohár wrote:
> > Ok, if wmi_requires_smbios_request is really doing nothing, then it
> > should not be used. It enables some QSET feature in Dell SMM mode which
> > is for 2 laptops.
> 
> It is also used to filter 0xe025 key code which is generated by 3rd key and is 
> visible via both atkbd and wmi:
> 
> ===
> 343     if (type == 0x0000 && code == 0xe025 && !wmi_requires_smbios_request)
> 344         return;
> ===
> 
> (see commit 13f5059ac5a6b)

Yes, this filtering is enabled and needed only when QSET feature was
activated. And is needed only for machines which need QSET feature.

> > Looks like that Dell Vostro 3360 have this meaning for multimedia keys:
> > 
> > first key: Mobility Center
> > second key: Dell Support Center
> > third key: Dell Instant Launch Manager
> > 
> > (same as other Vostro laptops)
> 
> Likely, yes. At least, for Launch Manager (key "3") there is a record in the 
> table:
> 
> ===
> 135     /* Dell Instant Launch key */
> 136     { KE_KEY,    0xe025, { KEY_PROG4 } },
> ===
> 
> As for Mobility Center, relevant key is commented out and has completely 
> different keycode:
> 
> ===
> 150     /* Untested, Windows Mobility Center button on Inspiron 7520 */
> 151     /* { KE_IGNORE, 0xe02a, { KEY_RESERVED } }, */
> ===
> 
> For Support Center, it is not commented, but still reserved:
> 
> ===
> 189     /* Dell Support Center key */
> 190     { KE_IGNORE, 0xe06e, { KEY_RESERVED } },
> ===

In both cases important is KE_IGNORE, which fully drops those events. So
IIRC we used KEY_RESERVED as it is irrelevant which key code is defined for
dropped events.

> > But do not know what KEY_* are used on other Vostro laptops for those
> > keys. It would be great to use same KEY_*...
> 
> So, according to what I see above, it looks like KEY_PROG(X) pattern should be 
> followed.
> 
> > > Well, I've tried. The problem is that if I even configure this key
> > > via setkeycodes, it doesn't work.
> > 
> > Hm... why it does not work?
> > 
> > CCing Dmitry, can you tell us what needs to be done to "active" key from
> > AT Keyboard driver which prints following messages to dmesg?
> 
> Just to note what I did. Here is my custom /etc/udev/hwdb.d/90-dell-
> vostro-3360.hwdb:
> 
> ===
> evdev:atkbd:dmi:bvnDellInc.:bvrA18:bd09/25/2013:svnDellInc.:pnVostro3360:pvr:rvnDellInc.:rn0F5DWF:rvrA00:cvnDellInc.:ct8:cvr0.1:
>   KEYBOARD_KEY_60=prog4
> ===
> 
> Here is how this key press is being detected by evtest via atkbd:
> 
> ===
> Event: time 1511289883.083968, type 4 (EV_MSC), code 4 (MSC_SCAN), value 60
> Event: time 1511289883.083968, type 1 (EV_KEY), code 203 (KEY_PROG4), value 2
> Event: time 1511289883.083968, -------------- SYN_REPORT ------------
> ===

So, it is working fine and there is no problem in kernel.

> But xev shows nothing when I press this key. Am I doing something wrong?

This is bug in X Server or so. You would need to remap keycode to
something different as a workaround for X Server.

> > In dell-wmi we filter all key events which are also delivered via PS/2
> > AT Keyboard driver. So filtering PS/2 keys instead of WMI is anti-design
> > solution.
> 
> Well, sounds reasonable...
> 
> Thanks.
> 
> Regards,
>   Oleksandr

-- 
Pali Rohár
pali.rohar@...il.com

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