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

From: Geert Uytterhoeven
Date: Fri Sep 26 2014 - 02:25:39 EST

Hi Kevin,

On Thu, Sep 25, 2014 at 11:31 PM, Kevin Hilman <khilman@xxxxxxxxxx> wrote:
> Geert Uytterhoeven <geert+renesas@xxxxxxxxx> 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@xxxxxxxxx>
>> ---
>> 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.



Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx

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
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