Re: [PATCH v3 3/5] clk: introduce the common clock framework

From: Mark Brown
Date: Thu Dec 01 2011 - 09:42:20 EST


On Wed, Nov 30, 2011 at 11:39:59PM -0700, Paul Walmsley wrote:

> Clock rate/parent-change notifiers are requirements for DVFS use-cases,
> and they must be paired with something like the
> clk_{allow,block}_rate_change() functions to work efficiently. I intend
> to comment on this later; it's not a simple problem. It might be worth
> noting that Tero and I implemented a simplified version of this for the
> N900.

I'm thinking that if we're going to have clk_{allow,block}_rate_change()
we may as well make that the main interface to enable rate changes - if
a device wants to change the clock rate it allows rate changes using
that interface rather than by disabling the clocks. I've got devices
which can do glitch free updates of active clocks so having to disable
would be a real restriction, and cpufreq would have issues with actually
disabling the clock too I expect.
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/