Re: [PATCH] fujitsu-laptop: Support radio LED

From: Darren Hart
Date: Sat Apr 09 2016 - 22:33:34 EST


On Thu, Mar 24, 2016 at 10:05:14PM +1030, Jonathan Woithe wrote:
> This is a quick reply with preliminary information. I'll follow up in the
> next few days with further details.
>
> On Tue, Mar 22, 2016 at 02:30:51PM +0100, Micha?? K??pie?? wrote:
> > > > As for detecting whether the LED is present on a given machine, I had to
> > > > resort to educated guesswork. I assumed this LED is present on all
> > > > devices which have a radio toggle button instead of a slider. My
> > > > Lifebook E744 holds 0x01010001 in BTNI. By comparing the bits and
> > > > buttons with those of a Lifebook E8420 (BTNI=0x000F0101, has a slider),
> > > > I put my money on bit 24 as the indicator of the radio toggle button
> > > > being present.
> > >
> > > The other question is how consistent the bit layout is across all devices
> > > which might make use of this driver. The set of potential devices spans
> > > nearly 10 years, and in many ways it would be surprising if the bit
> > > definitions were kept the same over that time. Testing would be the only
> > > way to get a feeling for that.
> >
> > My thoughts exactly.
> >
> > > If you could let me know how you went about
> > > acquiring the values on your machine I could try the exact same steps on the
> > > S7020 to see what we get.
> >
> > The BTNI value is printed to the kernel log buffer by
> > acpi_fujitsu_hotkey_add(), so all it takes to retrieve it is:
> >
> > dmesg | grep BTNI
>
> Here's what's reported by the S7020:
>
> fujitsu_laptop: BTNI: [0xf0001]
>
> The S7020 doesn't have any LEDs. It also has a physical slider to enable RF
> and an "RF enabled" indicator in the LCD panel. The LCD indicator is under
> hardware control; software cannot influence it.
>
> Clearly bit 24 is *not* set on the S7020. Using this bit as a test for the
> button's presence therefore should not cause trouble for the S7020 and
> probably other similar models from that time. Obviously we don't have
> access to every single model, but the apparent consistency back to the S7020
> is encouraging.
>
> > > > While it's not essential, it would be nice to initialize soft rfkill
> > > > state of all radio transmitters to the value of RFSW upon boot.
> > >
> > > I think this would only be necessary for those machines with the RF button
> > > in place of the hard slider switch, right?
> >
> > Yes. On the E8420 I tested, moving the slider switch to "off" position
> > caused the Bluetooth device to be removed from the system altogether
> > while iwlwifi reacted by hard-blocking phy0.
>
> I haven't noticed anything that dramatic on the S7020, but anything's
> possible.

Jonathan, MichaÅ,

Where are we with this? The above reads as "Doesn't appear to break existing
systems on hand". Jonathan, are you happy with this patch?

MichaÅ, do you have plans for a v2?

--
Darren Hart
Intel Open Source Technology Center