linux-kernel - Re: [PATCH 1/4] regulator: core: Support trying to get close to a certain voltage

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] [day] [month] [year] [list]

Message-ID: <20141216131324.GS11764@sirena.org.uk>
Date:	Tue, 16 Dec 2014 13:13:24 +0000
From:	Mark Brown <broonie@...nel.org>
To:	Doug Anderson <dianders@...omium.org>
Cc:	Alexandru Stan <amstan@...omium.org>,
	Ulf Hansson <ulf.hansson@...aro.org>,
	Heiko Stuebner <heiko@...ech.de>,
	Jaehoon Chung <jh80.chung@...sung.com>,
	Seungwon Jeon <tgih.jun@...sung.com>,
	Alim Akhtar <alim.akhtar@...sung.com>,
	Sonny Rao <sonnyrao@...omium.org>,
	Andrew Bresticker <abrestic@...omium.org>,
	"open list:ARM/Rockchip SoC..." <linux-rockchip@...ts.infradead.org>,
	"linux-arm-kernel@...ts.infradead.org" 
	<linux-arm-kernel@...ts.infradead.org>,
	Liam Girdwood <lgirdwood@...il.com>,
	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH 1/4] regulator: core: Support trying to get close to a
 certain voltage

On Mon, Dec 15, 2014 at 02:11:02PM -0800, Doug Anderson wrote:
> On Fri, Dec 12, 2014 at 4:59 AM, Mark Brown <broonie@...nel.org> wrote:

> > Perhaps doing something based on the various factorings out of the
> > voltage mapping would do the trick, add a new op for getting to the
> > closest voltage?

> I'd really rather add a new op because I think it would mean that all
> the old regulators that don't implement the op would be slow all of a
> sudden.  :(

Assuming there's a not missing there...  I don't think it's quite that
bad, most regulators do use one of the standard mapping functions and
for those that are likely to matter for performance there's usually a
calculation rather than a lookup table.  That said...

> I looked at trying to refactor everything, but I think the answer is
> that I should drop my patch and consider the existing
> regulator_set_voltage_tol() experience good enough.  While I could go
> through and try to make regulator_set_voltage_tol() better:

...I do agree that the current situation is probably adequate though,
the optimisation would be nice but it's mainly going to benefit corner
cases.

Download attachment "signature.asc" of type "application/pgp-signature" (474 bytes)