Re: So, what's the status on the recent patches here?

Pavel Machek
2006-08-30T22:43:52Z

On Tue 2006-08-29 21:52:26, David Singleton wrote:
> On 8/29/06, Pavel Machek <pavel@ucw.cz> wrote:
> >Hi!

> >> >> /sys/power/operating_points/high
> >> >> /sys/power/operating_points/highest
> >> >> /sys/power/operating_points/low
> >> >> /sys/power/operating_points/lowest
> >> >> /sys/power/operating_points/medium
> >> >> /sys/power/operating_points/mem
> >> >> /sys/power/operating_points/standby
....
> >That does not make mixing them right.
>
> Both OpPoint and PowerOp are going to 'mix' frequency, voltage
> and sleep states into their operating point concepts.
>
> The point was not to make it look like I was mixing sleep states and
> CPU frequency states, but to present all the power states
> supported by the system in one place and with one interface. It simplifies
> not only kernel code, but power manager code as well.

It is also wrong. And no, I do not think your power manager can
properly use "mem" state.

You see, "mem" is very different from lowest. To exit lowest, you have
to "echo highest > state". To exit "mem", you need power
button. That's very different operation.

> >> Perhaps, but the common name space makes it easy for the
> >> power manager
> >> daemon to perform the same functions without having to
> >> know that the lowest
> >> speed on my laptop is 600Mhz.
> >
> >And enumerate english strings in power daemon? Limiting the numver of
> >states?
>
> Hah, I didn't think of it that way. I was thinking in the same way
> "mem" and "disk" and "standy" are strings in the kernel.

> The names themselves don't mean anything other than to imply an order so the
> kernel and power manager can understand the same order.

mem/disk/standby are strings, because they can not be easily turned
into numbers. "low"/"lowest"/"high"/"highest" mess can easily be
turned into numbers. And that's what cpufreq does, btw.
Pavel
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