linux-kernel - Re: [PATCH 0/4] power: supply: add charge_behaviour property (force-discharge, inhibit-charge)

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20211203213305.dfjedjj3b25ftj2z@earth.universe>
Date:   Fri, 3 Dec 2021 22:33:05 +0100
From:   Sebastian Reichel <sebastian.reichel@...labora.com>
To:     Thomas Weißschuh <linux@...ssschuh.net>
Cc:     linux-pm@...r.kernel.org, ibm-acpi-devel@...ts.sourceforge.net,
        platform-driver-x86@...r.kernel.org,
        Mark Gross <markgross@...nel.org>,
        Hans de Goede <hdegoede@...hat.com>,
        Henrique de Moraes Holschuh <hmh@....eng.br>,
        linux-kernel@...r.kernel.org, linrunner@....net, bberg@...hat.com,
        hadess@...ess.net, markpearson@...ovo.com,
        nicolopiazzalunga@...il.com, njoshi1@...ovo.com, smclt30p@...il.com
Subject: Re: [PATCH 0/4] power: supply: add charge_behaviour property
 (force-discharge, inhibit-charge)

Hi,

On Wed, Nov 24, 2021 at 12:27:00AM +0100, Thomas Weißschuh wrote:
> This series adds support for the charge_behaviour property to the power
> subsystem and thinkpad_acpi driver.
> 
> As thinkpad_acpi has to use the 'struct power_supply' created by the generic
> ACPI driver it has to rely on custom sysfs attributes instead of proper
> power_supply properties to implement this property.
> 
> Patch 1: Adds the power_supply documentation and basic public API
> Patch 2: Adds helpers to power_supply core to help drivers implement the
>   charge_behaviour attribute
> Patch 3: Adds support for force-discharge to thinkpad_acpi.
> Patch 4: Adds support for inhibit-discharge to thinkpad_acpi.
> 
> Patch 3 and 4 are largely taken from other patches and adapted to the new API.
> (Links are in the patch trailer)
> 
> Ognjen Galic:
> 
> Your S-o-b is on the original inhibit_charge and force_discharge patches.
> I would like to add you as Co-developed-by but to do that it will also require
> your S-o-b. Could you give your sign-offs for the new patches, so you can be
> properly attributed?
> 
> Sebastian Reichel:
> 
> Currently the series does not actually support the property as a proper
> powersupply property handled fully by power_supply_sysfs.c because there would
> be no user for this property.

I'm not too happy how the acpi-battery hooks work, but that's not
your fault and this patchset does not really make the situation
worse. So:

Acked-by: Sebastian Reichel <sebastian.reichel@...labora.com>

-- Sebastian

> Previous discussions about the API:
> 
> https://lore.kernel.org/platform-driver-x86/20211108192852.357473-1-linux@weissschuh.net/
> https://lore.kernel.org/platform-driver-x86/21569a89-8303-8573-05fb-c2fec29983d1@gmail.com/
> 
> v1: https://lore.kernel.org/lkml/20211113104225.141333-1-linux@weissschuh.net/
> v1 -> v2:
> 
> * Use sysfs_emit-APIs instead of plain sprintf
> * More cecks for actual feature availability
> * Validation of the written values
> * Read inhibit-charge via BICG instead of PSSG (peak shift state)
> * Don't mangle error numbers in charge_behaviour_store()
> 
> Open points:
> 
> Thomas Koch has observed that on a T450s with two batteries
> inhibit-charge on BAT0 will affect both batteries and for BAT1 it is ignored
> entirely, this seems to be a bug in the EC.
> On my T460s with two batteries it works correctly.
> 
> Thomas Weißschuh (4):
>   power: supply: add charge_behaviour attributes
>   power: supply: add helpers for charge_behaviour sysfs
>   platform/x86: thinkpad_acpi: support force-discharge
>   platform/x86: thinkpad_acpi: support inhibit-charge
> 
>  Documentation/ABI/testing/sysfs-class-power |  14 ++
>  drivers/platform/x86/thinkpad_acpi.c        | 191 +++++++++++++++++++-
>  drivers/power/supply/power_supply_sysfs.c   |  51 ++++++
>  include/linux/power_supply.h                |  16 ++
>  4 files changed, 268 insertions(+), 4 deletions(-)
> 
> 
> base-commit: 66f4beaa6c1d28161f534471484b2daa2de1dce0
> -- 
> 2.34.0
> 

Download attachment "signature.asc" of type "application/pgp-signature" (834 bytes)