linux-kernel - Re: [PATCH/RFC v2 02/12] PM / Domains: Add DT bindings for PM QoS device latencies

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: <CAMuHMdVp6MiPb8Dhph=eyTgsnBbQSzEHbA9TOjCDi=7BM8GgTg@mail.gmail.com>
Date:	Fri, 26 Sep 2014 08:25:26 +0200
From:	Geert Uytterhoeven <geert@...ux-m68k.org>
To:	Kevin Hilman <khilman@...nel.org>
Cc:	Geert Uytterhoeven <geert+renesas@...der.be>,
	"Rafael J. Wysocki" <rjw@...ysocki.net>,
	Len Brown <len.brown@...el.com>, Pavel Machek <pavel@....cz>,
	Simon Horman <horms@...ge.net.au>,
	Magnus Damm <magnus.damm@...il.com>,
	Rob Herring <robh+dt@...nel.org>,
	Pawel Moll <pawel.moll@....com>,
	Mark Rutland <mark.rutland@....com>,
	Ian Campbell <ijc+devicetree@...lion.org.uk>,
	Kumar Gala <galak@...eaurora.org>,
	Ulf Hansson <ulf.hansson@...aro.org>,
	Tomasz Figa <tomasz.figa@...il.com>,
	Philipp Zabel <philipp.zabel@...il.com>,
	Grygorii Strashko <grygorii.strashko@...com>,
	Linux PM list <linux-pm@...r.kernel.org>,
	"devicetree@...r.kernel.org" <devicetree@...r.kernel.org>,
	Linux-sh list <linux-sh@...r.kernel.org>,
	"linux-arm-kernel@...ts.infradead.org" 
	<linux-arm-kernel@...ts.infradead.org>,
	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH/RFC v2 02/12] PM / Domains: Add DT bindings for PM QoS
 device latencies

Hi Kevin,

On Thu, Sep 25, 2014 at 11:31 PM, Kevin Hilman <khilman@...nel.org> wrote:
> Geert Uytterhoeven <geert+renesas@...der.be> writes:
>> PM QoS device start/stop and save/restore state latencies are more or
>> less properties of the hardware.
>> In legacy code, they're specified from platform code.
>> On DT platforms, their values should come from DT.
>>
>> Signed-off-by: Geert Uytterhoeven <geert+renesas@...der.be>
>> ---
>> Should these properties be called "linux,*-latency"?
>
> Hmm, the start/stop latencies are clearly properties of the hardware,
> but the save/restore latencies seem to be a function of the driver.
> e.g., some drivers may keep a shadow copy of their registers in memory
> so the save time is minimized.
>
> I don't have too strong of an opinion on this, but probably the drivers
> should just add their own values to the start/stop latencies to add the
> linux specific overhead.

Thanks. I agree with you on this, so I'll remove the save/restore latencies.

Gr{oetje,eeting}s,

                        Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@...ux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds
--
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/