linux-kernel - Re: "cpufreq: fix serialization issues with freq change notifiers" breaks cpufreq too

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: <3488595.xbBYlylYai@vostro.rjw.lan>
Date:	Thu, 12 Sep 2013 13:01:35 +0200
From:	"Rafael J. Wysocki" <rjw@...ysocki.net>
To:	Viresh Kumar <viresh.kumar@...aro.org>
Cc:	"Rafael J. Wysocki" <rafael.j.wysocki@...el.com>,
	Guennadi Liakhovetski <g.liakhovetski@....de>,
	Greg KH <greg@...ah.com>,
	Linux Kernel Mailing List <linux-kernel@...r.kernel.org>,
	"linux-arm-kernel@...ts.infradead.org" 
	<linux-arm-kernel@...ts.infradead.org>,
	"linux-pm@...r.kernel.org" <linux-pm@...r.kernel.org>,
	"cpufreq@...r.kernel.org" <cpufreq@...r.kernel.org>,
	SH-Linux <linux-sh@...r.kernel.org>,
	Magnus Damm <magnus.damm@...il.com>
Subject: Re: "cpufreq: fix serialization issues with freq change notifiers" breaks cpufreq too

On Thursday, September 12, 2013 11:06:14 AM Viresh Kumar wrote:
> On 12 September 2013 06:13, Rafael J. Wysocki
> <rafael.j.wysocki@...el.com> wrote:
> > Yes, if you can point to a specific driver having this problem.
> 
> There are so many of those (I know it because I went through almost all drivers
> recently with my cleanup series): cpufreq-cpu0, omap-cpufreq,
> exynos-cpufreq, etc..
> 
> They all do this:
> 
> A. If new freq is more than old: Increase voltage
> B. Change freq
> C. If new freq is less than old: decrease voltage

Well, if there's more than one it's even simpler.  You can just pick one. :-)

Like, "for example, <driver name> does the following ... which may cause the
hardware to misbehave, because ...".

Thanks,
Rafael

--
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/