@Modest-Polykarpovich 16 MB just for experiment, but I need about 4 MB of contiguous memory for my DMA audio buffer, of course it works in kernel-mode. If it's interesting for u, u can read this article
Oh, you are trying to make your own sound driver - very well, keep me in touch, I'd like to use I2S Audio Interface too. Perhaps it's no need, because many people want sound on MIPS, many Audio Codecs Chips vendors wants to sell it, the drivers are must be. We can only select a chip. And sound driver is a very difficult, I think better choose professional variants.
It's Audio Codec WM8960 on the OpenWRT via I2S interface.