RE: [PATCH 3/4] dell-wmi: Add information about other WMI event codes

Mario_Limonciello
2016-06-22T14:28:42Z

> -----Original Message-----
> From: Pali Rohár [mailto:pali.rohar@gmail.com]
> Sent: Wednesday, June 22, 2016 9:24 AM
> To: Limonciello, Mario <Mario_Limonciello@Dell.com>
> Cc: gabriele.mzt@gmail.com; mjg59@srcf.ucam.org; dvhart@infradead.org;
> kernel@kempniu.pl; luto@kernel.org; alex.hung@canonical.com; platform-
> driver-x86@vger.kernel.org; linux-kernel@vger.kernel.org
> Subject: Re: [PATCH 3/4] dell-wmi: Add information about other WMI event
> codes
>
> On Wednesday 22 June 2016 14:21:25 Mario_Limonciello@Dell.com wrote:
> > > > For Linux I don’t think this is necessary and a NOOP is appropriate.
> > > >
> > > > There is also a second place that some older laptops had a battery
> "hotkey"
> > > > that would also emit 0xE00E. This was also picked up by quickset and
> would
> > > > show battery information.
> > > >
> > > > This shouldn't be blocked by kernel, I'd expect if someone wants to
> bind
> > > this
> > > > to another application from userspace they should be able to.
> > >
> > > Great! Can I send patch after which 0xe00e will be send to input layer as
> > > event KEY_BATTERY?
> > >
> >
> > Well that's why I was mentioning this in two places. If it's received from
> keyboard
> > recoding it as KEY_BATTERY sounds appropriate to me. If it's received from
> WMI,
> > it really shouldn't be set as anything for Linux to do.
> >
> > I don't think any apps will benefit from the notification to re-read battery
> > Information today.
>
> I mean for dell-wmi.c code.
> Why it should not be set to anything on Linux?
>

On Windows Quickset is a separate application from built-in Windows battery
applet. It shows similar types of information as gnome-power-manager does,
but because it's not part of the OS, it doesn't get notifications like this so
special BIOS hooks are in place for it to know when to re-read battery
information.

On Linux, there are already infrastructure for battery removal and adding
notifications from ACPI. Sending this up to user space won't be useful.