lossage. On the Alpha, we force the buffers to be allocated through the SGMAP
so that the PCI bus addresses are low enough.
At least it's only one line of code...
Also fix some typos and add more debugging printf()s.
This would work on the Alpha, but the card I have appears to have the upper
address bits chopped off, and the ring buffer gets mapped using the DGMAP,
which uses the upper bits. Boom.
* Use the trigger interface.
* Permit different encodings for record and playback.
* Set AUDIO_PROP_INDEPENDENT.
* Fix the mmap(2) hole again.
* Use 16-bit mode for a-law and u-law playback.