[alsa-devel] [PATCH 2/2 v2] ASoC: arizona: Improve ultrasonic frequency response

Charles Keepax ckeepax at opensource.wolfsonmicro.com
Tue Feb 4 10:17:58 CET 2014

On Tue, Feb 04, 2014 at 12:17:27AM +0000, Mark Brown wrote:
> On Fri, Jan 31, 2014 at 04:16:18PM +0000, Charles Keepax wrote:
> > Evaluation of the device has given some settings to improve the
> > ultrasonic frequency response. However, this may cause sub-optimal
> > performance in system designs with high output gains on the headphone
> > path (0dB or -2dB), and as the frequencies are inaudible anyway some
> > users may not desire higher frequency response at those frequencies.
> > So allow the user the option to select it if it is appopriate for
> > their system design.
> Reading what you're saying here I can't help but think that this sounds
> like it may be use case dependent as well and therefore something that
> ought to be runtime controllable depending on if ultrasonics and/or line
> level outputs are in use (0dB isn't high gain, it's no gain!) for
> example.

I think in practice it will likely be set once for a given
system. Although that said there is nothing that would prevent
this being switchable at runtime, I will look into respinning it
with runtime control.


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