[alsa-devel] HR timer 1000Hz limit since kernel 4.4.0-77

[Takashi Iwai]

On Mon, 22 May 2017 18:30:27 +0200,
Tim wrote:
> 
> Hello, ever since kernel 4.4.0-77, there seems to be
>  a limit on the ALSA HR timer, I can't set it above 1000Hz
>  (snd_timer_params() fails with -22 invalid argument).
> I used to be able to set the rate much higher than that.
> Been observed in two completely different distros, one with
>  a much newer kernel. How can I overcome this limit?

It's a recently introduced limit to avoid the too condensed spinlocks
that may lead to a kernel lockup (the commit 71321eb3f2d0).
If sub-ms timer is really required, we may introduce some module
option to allow it, but it's the last-resort.

What's the exact use case?


thanks,

Takashi