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

From: Kevin Hilman
Date: Thu Sep 25 2014 - 17:31:49 EST

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.

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