power managing maestro.c 0.14 available.

[Jamie Lokier]

Zach Brown wrote:
> The big new exciting feature is the concept of power managment
> in the driver.  The driver now keeps the chip in a lower
> power state while idle.  (it just keeps enough going to 
> keep the ac97 fed so things like the on board CD work.)
> It turns things on and off as /dev/dsp is accessed.

This is very cool.  I hope all the devices on my laptop get treated
similarly eventually.

> It also
> powers the chip down entirely when the module is removed.

Does this mean

   (a) extra power is consumed while the driver is loaded but no CD is
       playing?

   (b) when the module is auto-unloaded, the CD sound stops?

(a) could be made a bit better by turning the power off completely when
the input mixer levels are zeroed.

(b) seems reasonable but is unlike other sound drivers.  With the other
drivers, you open /dev/mixer which autoloads the module, set the mixer
values, close /dev/mixer, play your CD, and the module is auto-unloaded
within a minute or two.  CD sound usually continues.

It doesn't take a leap of imagination to imagine that the CD driver or
player software might be convinced to zero the CD mixer input level when
not in use, some day.

have a radiant day,
-- Jamie

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