On Sat, Dec 24, 2011 at 11:52:29PM +0800, Richard Zhao wrote:

On Sat, Dec 24, 2011 at 01:42:29PM +0000, Mark Brown wrote:

quoted

On Sat, Dec 24, 2011 at 09:28:33PM +0800, Richard Zhao wrote:

quoted

quoted

If you think regulator thansition latency is board specific, then the board
dts can overrite it.

quoted

We should just query this information from the regulator subsystem
(there's hooks but currently nothing implements them).  The regulators
can define their own bindings if they need to read it from device tree,
most of them should be able to do this as a function of knowing about
the device.  None of this is specific to cpufreq so cpufreq shouldn't
have to define its own support for this.

I'd like to query the latency by call clk and regulator APIs. but as you said
both of them have not implemented it yet. I think, for now, we can use the

The *call* is there in the regulator subsystem, it's just that none of
the drivers back it up with an actual implementation yet.  Which turns
out to be a good thing as cpufreq can't currently understand variable
latencies and the governors don't deal well with non-trivial latencies
anyway.

property to get the total latency. Once I can get it at runtime, I'll remove
it. So the definition of trans-latency is just the same as cpufreq transition_latency,
people get less confused. What do you think?

The problem with device tree is that once you've defined a binding
you're stuck with it, it's very hard to change - witness all the magic
number based stuff with the interrupt bindings for example