On Thu, 27 Dec 2018 07:46:57 +0100, S.j. Wang wrote:
I still have two questions:
It seems the no-period-wakeup feature should be dropped for it isn't recommended By alsa, right? I still found some driver in kernel support it, what's the reason?
Shall we add this option in aplay for it is feature that alsa support, even it is optional?
As Sakamoto-san already mentioned, no-period-wakeup is nothing but an optional feature for very specific applications and setup, and it's still valid and useful.
The condition to use this option is: - If a hardware may perform DMA continuously on a ring buffer (a la free-wheel mode), and - Application doesn't need the wakeup from kernel at each PCM period, but it manages the stream transfer timing by itself.
aplay doesn't satisfies the latter, hence adding such a command line option makes no sense. But, it doesn't mean that no-period-wakeup is useless. It can work well for specific applications like PulseAudio.
Takashi