[alsa-devel] [PATCH v5] ASoC: add RT286 CODEC driver
bardliao at realtek.com
Fri Mar 14 10:38:20 CET 2014
> -----Original Message-----
> From: Mark Brown [mailto:broonie at kernel.org]
> Sent: Friday, March 14, 2014 4:43 AM
> To: Takashi Iwai
> Cc: Lars-Peter Clausen; Bard Liao; Oder Chiou; alsa-devel at alsa-project.org;
> lgirdwood at gmail.com; Gustaw Lewandowski; Flove
> Subject: Re: [alsa-devel] [PATCH v5] ASoC: add RT286 CODEC driver
> 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).
What's your suggestion of the I/O part of rt286 codec driver?
Can I keep using regmap without using its cache?
Or it is better not using regmap in this driver?
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