linux-kernel - Re: [PATCH][ACPI] AC/DC notifier

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: <21d7e9970910070116h6cf4e472i309537e9b4bb1e08@mail.gmail.com>
Date:	Wed, 7 Oct 2009 18:16:29 +1000
From:	Dave Airlie <airlied@...il.com>
To:	Pavel Machek <pavel@....cz>
Cc:	"Tippett, Matthew" <matthew.tippett@....com>,
	Willy Tarreau <w@....eu>,
	Matthew Garrett <mjg59@...f.ucam.org>,
	"Langsdorf, Mark" <mark.langsdorf@....com>, lenb@...nel.org,
	linux-acpi@...r.kernel.org, linux-kernel@...r.kernel.org,
	"Li, Samuel" <Samuel.Li@....com>
Subject: Re: [PATCH][ACPI] AC/DC notifier

On Wed, Oct 7, 2009 at 5:31 PM, Pavel Machek <pavel@....cz> wrote:
> On Tue 2009-10-06 10:53:22, Tippett, Matthew wrote:
>> (Resending as text-only - sorry)
>>
>> Bringing this item back up again.
>>
>> I am not suggesting that the application of any particular policy
>> appears within the kernel or userspace or a secondary policy engine.
>> In general I am also against codifying policy within drivers.
>>
>> I am interested seeing the ACPI notifier mechanism expanded to allow
>> AC/DC state changes propagate to other kernel drivers without requiring
>> a userspace in between.
>>
>> I can continue to come up with real scenarios that would possibly
>> require kernel-to-kernel notification, but would rather focus this
>> discussion of the pure technical issues associated with adding the
>> notifier to the AC/DC ACPI subsystem.
>
> Please do. So far you did not show valid use for such notifier.
>
> (Ok, I know of one. Old amd64 notebooks had cpufreq scaling enabled,
> with battery unable to supply enough current to feed the CPU at
> highest cpufreq setting. At that point, scaling cpufreq down at unplug
> is correctness issue, and AC/DC notifier in kernel makes
> sense.)
>
> So... what do you want to use it for?

I'm not sure we have a open driver use case for this, if not I suggest
we remove it and only add it when a user is added to the kernel.

Dave.
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/