Re: [PATCH] ACPI: battery: Fix bogus cycle count values on systems without _BIX

[Rafael J. Wysocki (Intel)]

On Thu, Sep 10, 2026 at 12:40 AM Armin Wolf <W_Armin@xxxxxx> wrote:
>
> Am 09.09.26 um 16:27 schrieb Rafael J. Wysocki (Intel):
>
> > On Tue, Sep 1, 2026 at 10:18 PM Armin Wolf <W_Armin@xxxxxx> wrote:
> >> Am 01.09.26 um 22:16 schrieb Rafael J. Wysocki (Intel):
> >>
> >>> On Tue, Sep 1, 2026 at 10:11 PM Armin Wolf <W_Armin@xxxxxx> wrote:
> >>>> Am 07.08.26 um 01:38 schrieb Armin Wolf:
> >>>>
> >>>>> Devices supporting only the legacy _BIF ACPI control method cannot
> >>>>> know the cycle count of the associated battery, so cycle_count always
> >>>>> remains 0. Claiming support for POWER_SUPPLY_PROP_CYCLE_COUNT on
> >>>>> such devices can thus mislead userspace applications and prevents
> >>>>> power supply extensions from supplying correct cycle count values.
> >>>>>
> >>>>> Fix this by not claiming support for POWER_SUPPLY_PROP_CYCLE_COUNT
> >>>>> on devices without _BIX.
> >>>> Any thoughts on this? I tested it on my device, and so far everything seems
> >>>> to work flawlessly.
> >>> It looks good overall, but it is quite substantial, which is why it
> >>> didn't make it into 7.3-rc1.
> >>>
> >>> I'm planning to apply it for 7.4.
> >> Alright, that works for me.
> > And so applied.
> >
> > Sashiko has a comment on the _BIX failing case:
> >
> > https://sashiko.dev/#/patchset/20260806233817.622975-1-W_Armin%40gmx.de
> >
> > but this can be addressed on top of the current patch IMV.
> >
> > If you think that it's worth addressing, please send a follow-up one for that.
> >
> > Thanks!
>
> Thank you :)
>
> I do not think that Sashiko is right in this case, as failures inside _BIX
> should _normally_ only be temporary. So i think the current strategy of temporally
> falling-back to _BIF if _BIX fails is fine.

Sounds good to me, thanks!