Re: [alsa-devel] snd-fireworks requires larger period sizes than FFADO

Dominic Sacré wrote:

I'm trying to use an Echo AudioFire 4 with the snd-fireworks driver. With FFADO the device works reasonably well at a period size of 64 samples (on a PREEMPT_RT kernel), whereas with snd-fireworks the lowest possible period size seems to be 256 samples.

The lowest achievable analog roundtrip latency seems to be around 19ms (at 2x256 frames), as opposed to 8.3ms with FFADO (at 2x64). Are there any known limitations of the snd-fireworks driver in this regard?

At the moment, the driver uses a minimum period size of 5 ms.

You could try reducing INTERRUPT_INTERVAL and the parameter to snd_pcm_hw_constraint_minmax() in sound/firewire/amdtp-stream.c, and recompiling the driver.

Regards, Clemens