Re: [PATCH v13 4/4] battery: Add the ThinkPad "Not Charging" quirk

[Henrique de Moraes Holschuh <hmh@hmh.eng.br>]

On Wed, 07 Feb 2018, Ognjen Galic wrote:
> The EC/ACPI firmware on Lenovo ThinkPads used to report a status
> of "Unknown" when the battery is between the charge start and
> charge stop thresholds. On Windows, it reports "Not Charging"
> so the quirk has been added to also report correctly.
> 
> Now the "status" attribute returns "Not Charging" when the
> battery on ThinkPads is not physicaly charging.
> 
> Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
> Signed-off-by: Ognjen Galic <smclt30p@gmail.com>

AFAIK, This behavior goes back to the initial SBS implementation in the
IBM era ECs of the Thinkpads...  We've always called it "idle" in the
linux-thinkpad community.  The behavior comes from SBS
(http://smartbattery.org/specs/), the EC was reporting its status
(charging/not charging *THIS* battery) in one bit, and the battery's
status (discharging/not discharging *THIS* battery) in a different bit.

It was rather simple to observe the behavior of those bits in a
two-battery system.

Would that apply to these newer Lenovo models?  If so, you might want to
consider using "idle", instead. "not charging" does _not_ imply "neither
charging nor discharging", while "idle" does.

-- 
  Henrique Holschuh