13 Mar
2014
13 Mar
'14
9:43 p.m.
On Thu, Mar 13, 2014 at 09:04:49PM +0100, Takashi Iwai wrote:
Mark Brown wrote:
We don't really *need* the cache, it just makes it easier to do resume and gives a bit of a performance boost.
Well, the caching isn't just a bit. Without caching, you'd have to whip the sound hardware powered up/down at each time querying the current mixer value.
Realistically most hardware can't actually do that - there's a couple of the idle_bias_off devices that have built in LDOs which can but it's relatively unusual to be able to remove enough power to loose register I/O (and in any case you wind up needing to cache the values per control or something in order to do system suspend).