linux-kernel - Re: [PATCH 5/7] platform/x86: fujitsu-laptop: do not update ACPI device power status

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]

Date:   Wed, 21 Jun 2017 13:17:27 -0700
From:   Darren Hart <dvhart@...radead.org>
To:     Michał Kępień <kernel@...pniu.pl>
Cc:     Jonathan Woithe <jwoithe@...t42.net>,
        Andy Shevchenko <andy@...radead.org>,
        platform-driver-x86@...r.kernel.org, linux-acpi@...r.kernel.org,
        linux-kernel@...r.kernel.org
Subject: Re: [PATCH 5/7] platform/x86: fujitsu-laptop: do not update ACPI
 device power status

On Fri, Jun 16, 2017 at 06:40:56AM +0200, Michał Kępień wrote:
> Calling acpi_bus_update_power() for ACPI devices FUJ02B1 and FUJ02E3 is
> pointless as they are not power manageable (neither _PS0 nor _PR0 is
> defined for any of them), which causes their power state to be inherited
> from their parent devices.  Given the ACPI paths of these two devices
> (\_SB.PCI0.LPCB.FJEX, \_SB.FEXT), their parent devices are also not
> power manageable.  These parent devices will thus have their power state
> initialized to ACPI_STATE_D0, which in turn causes the power state for
> both FUJ02B1 and FUJ02E3 to always be ACPI_STATE_D0 ("on").
> 

How confident are we that all implementations of these two ACPI devices lack
_PS0 and _PR0 ?

-- 
Darren Hart
VMware Open Source Technology Center