Re: [PATCH 1/4] thinkpad_acpi: Add support for controlling chargethresholds

From: Henrique de Moraes Holschuh
Date: Mon Dec 30 2013 - 16:58:52 EST

On Mon, 30 Dec 2013, Julian Andres Klode wrote:
> On Mon, Nov 11, 2013 at 02:56:30PM +0100, Julian Andres Klode wrote:
> > Add support for battery charge thresholds in new Sandy Bridge and Ivy Bridge
> > ThinkPads. Based on the unofficial documentation in tpacpi-bat.
> >
> > The threshold files support the values '0' for the controller's default,
> > and 1-99 as percentages. Values outside of that range are rejected. The
> > behaviour of '0' might be confusing, especially for the stop case where
> > it basically seems to mean '100'.
> Thinking more about this, it might make more sense to simply accept a 100
> value and not accept a 0 value in the stop case (I tried multiple times to
> write 100 to a stop_charge_thresh file, because that feels more natural).
> Having a 0 mean 100% is just odd. So stop_charge_thresh should simply
> accepts integer values in the range [1, 100] (and start_charge_thresh
> should continue accept [0, 99], as 0 really means 0 there).

Indeed. Just return EINVAL for a stop threshold of 0.

"One disk to rule them all, One disk to find them. One disk to bring
them all and in the darkness grind them. In the Land of Redmond
where the shadows lie." -- The Silicon Valley Tarot
Henrique Holschuh
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at
Please read the FAQ at