Re: [PATCH] ACPI: battery: Add "Not Charging" quirk for Microsoft Surface devices

[Maximilian Luz]

On 5/6/22 20:43, Rafael J. Wysocki wrote:
> On Fri, Apr 29, 2022 at 7:41 PM Maximilian Luz <luzmaximilian@xxxxxxxxx> wrote:
> > Microsoft Surface devices have a limiter that sets a fixed maximum
> > charge capacity for the battery. When that maximum capacity has been
> > reached, charging stops. In that case, _BST returns a battery state
> > field with both "charging" and "discharging" bits cleared. The battery
> > driver, however, returns "unknown" as status.
> >
> > This seems to be the same behavior as observed on the ThinkPads, so
> > let's use the same quirk to handle that.
> >
> > Signed-off-by: Maximilian Luz <luzmaximilian@xxxxxxxxx>
> > ---
> >
> > For what it's worth, I don't think the ACPI spec explicitly states that
> > any of the status bits need to be set, or that there are only the
> > "charging" and "discharging" states. As far as I can tell, ACPI only
> > states:
> >
> >      Notice that the Charging bit and the Discharging bit are mutually
> >      exclusive and must not both be set at the same time. Even in
> >      critical state, hardware should report the corresponding
> >      charging/discharging state.
> >
> > But that does not exclude the case that no bit is set. So, strictly
> > going by spec, I don't think it's necessary to put all of this behind a
> > quirk.
>
> I think that this should be covered by the patch I've just applied:
>
> https://patchwork.kernel.org/project/linux-acpi/patch/20220427154053.499203-1-wse@xxxxxxxxxxxxxxxxxxx/
>
> Shouldn't it?

It does, thank you!

Sorry for having missed that one.

Regards,
Max