two DMA channels to do e.g. full-duplex. This allows
a way of specifying the second channel in a sane way.
THIS IS TEMPORARY. The drq2 locator will go away when
the locator system has been changed to allow multiple
values per locator.
- It is now possible to handle devices that want "looping" DMA,
e.g. the SoundBlaster correctly. The WSS and SB drivers use this.
To do this several new methods were introduced in audio_hw_if.
- Different silence handling (forced by previous change).
- The audio driver can now be mmap()-ed, but due to problems in
the VM system only for writing for now.
- The OSS (Linux) audio emulation takes advantage of some of the
new features.