Re: [alsa-devel] hw_params function and OSS emulation

Takashi Iwai wrote:

Err, usually, application = user-space application. Do you mean really this?

Yes. The application allocates a buffer, locks it down, and passes it to the kernel. Since the buffer was allocated in user space, it is virtual contiguous but not physically contiguous, hence the need for a list of physical addresses. To the hardware, the buffer appears as a collection of scattered buffers. Hence, scatter/gather.

Like I said, I haven't look at the ALSA API for S/G, so I may be talking about an implementation of S/G that does not apply to ALSA.