Re: [LAU] JACK and Sound OpenFirmware?

Kai Vehmanen <kvlists@nosignal.fi> writes:

> Hey,
>
> On Thu, 27 Aug 2020, Fons Adriaensen wrote:
>> On Thu, Aug 27, 2020 at 12:51:11PM +0300, Kai Vehmanen wrote:
>>> For reasons that predate my time in the team, the minimum period size for
>>> many Intel platforms has been set to 192 bytes (in the topology file, i.e.
>>
>> According to which stange rules would this value (192 = 3 * 2^6)
>> lead to 2^k being rejected and 2^k + 8 being accepted ??
>
> the constraint is simply that period size is a multiple of the minimum
> value. I think in the examples of this thread (which Wim quoted), JACK
> was run with stereo 32bit config, so the values would translate to:
>
> 120 frames -> 2*4*120=960 bytes (5*192)
> 264 frames -> 2*4*264=2112 bytes (11*192)
> 504 frames -> 2*4*504=4032 bytes (21*192)
> 2040 frames ->2*4*2048=16320 bytes (85*192)
> ...
>
> I don't think the constraint makes really sense, but that's what it is
> now (for all systems where 192 is the minimum period size). Luckily
> the param is read from user-space (ALSA tplg), so it's not hardcoded
> in kernel nor in firmware.

Thanks a lot for chiming in and shedding some light on this issue.
Also thanks for volunteering to get it fixed.
I am looking forward to that fix landing on my system.

-- 
CYa,
  ⡍⠁⠗⠊⠕
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