Codec sleep, saving power when idle

[dreamlayers]

On my 5G 30GB iPod, audiohw_close() (which puts the codec chip to sleep) saves about 7.5 mA.  More could probably be saved by shutting down some related hardware.  Of course, you can only do this when not playing or recording audio.  Is this a desirable feature?

If idle power consumption is reduced via this and other means, the end result could be similar to original firmware's sleep mode.  You could simply set an extremely long idle power-down time.

[saratoga]

I think at very least it would be nice to have the codec off when music isn't playing, even if we don't have a proper sleep mode.

[soap]

Desirable feature x10!

[Chronon]

+1 for codec sleep!

[Hillshum]

Do most targets have such hardware that could be shut off when unused?

[LambdaCalculus]

It's mostly the unused hardware in the iPods that we can do this with, but I'm sure there are other targets with hardware currently unused by Rockbox that we can do this with (Gigabeast?)

Also, +1 for codec sleep!

[Hillshum]

Also, do we know if the Broadcom video chip is using power?

[saratoga]

Also, do we know if the Broadcom video chip is using power?

Did you see this?

FS#9890 - iPod 5G: LCD sleep, BCM shutdown and bootstrap

[torne]

7.5mA seems like a pretty worthwhile improvement: my ipod draws only 25mA when idle with the LCD disabled, so cutting another 7.5 is indeed edging closer and closer to being able to leave it turned on