The following .dtsi file:
causes the mcasp davinci audio driver to load during boot,
and prevents overlays (like BB-BONE-AUDI-02) from setting
audio parameters. The result is hardware configuration errors
when trying to use ALSA commands:
Unable to set hw params for playback: Invalid argument
Setting of hwparams failed: Invalid argument
That .dtsi file enables spi0/1, and mcasp0/1. By removing
the mcasp0/1 entries, the BB-BONE-AUDI-02 overlay is able
to enable mcasp while configuring it properly, and allowing
the driver to work.
It's not clear to me how that file is an eDMA fix, nor why
it enables mcasp.
Here's the thread on the alsa-devel list where we figured it
Is the best way to report this problem here on the list like
this, or to open an issue on github/dtb-rebuilder?
Note that this is all with kernel 4.4.7-bone-rt-r9. Not sure
to how many other versions it applies.