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