[LAU] reducing xruns (System configuration)

[David Kastrup]

Ralf Mardorf <ralf.mardorf at alice-dsl.net> writes:

> On Thu, 2018-07-19 at 22:44 +0200, David Kastrup wrote:
>> You are babbling. [snip]
>> 
>> A lot of people get setups like that to work without rtirq .
>
> Hi,
>
> the OP on Wed, 2018-07-18 at 21:28 +0200 wrote "64 buffer size at 48kHz
> 2 Periods/Buffer" and the OP on Thu, 2018-07-19 at 14:32 +0200 wrote
> "Bus 003 Device 002: ID 08bb:29c2 Texas Instruments PCM2902C Audio CODEC".
>
> I'm not aware that a lot of people got this to work at all.

I missed the PCM2902C bit.  That chip is described in
http://www.ti.com/product/PCM2902C/technicaldocuments and is USB full
speed (namely USB1.1 speeds).  It is described as

    – USB Adaptive Mode for Playback
    – USB Asynchronous Mode for Record

It sports something like 16bit/48kHz with 89dB SNR.  That is both with
regard to attainable sound quality as well as USB bus behavior
completely lacklustre.  I'd expect this kind of interface to be mostly
soldered to mainboards directly where one would not expect to be able to
change buses at all.

Or be part of some USB sound interface in the $10 price class.

So the idea to take this into low-latency realms with a view on realtime
effects seems a bit optimistic indeed.  Actually out of place.  Maybe
this isn't actually the interface we are dealing with but just something
hardwired to the motherboard and thus cropping up in the lsusb output?

-- 
David Kastrup