USB HID knowledge wanted

[Børge Strand-Bergesen]

Hi guys, 

I've dug a bit more into the challenges of fixing volume control on Linux+UAC2 and frequency change on Win10 C.U.+UAC2. 

The closest thing I have to date is a messed-up HID implementation by yours truly.... 

My suspicion is that bugs in the HID implementation cause the different OSes to go into each their own fail-safe mode. I could be wrong about this, but it's the best lead to date. 

So, if anyone of you has experience in implementing HID on USB, please lend a hand. I can point you to what I believe are the biggest holes in the code base.

My hope is that a solid HID implementation will make the observed errors on Linux and Win10 C.U. easier to spot and fix. The first check could be to disable HID altogether. My most recent code is pushed to audio-widget-experimental.

On site in Norway I have firmware with plenty of RS232 debug, an Ellisys USB Explorer and various computers with TeamViewer. 

Børge

P.S. Why HID? Because it's cool! On my CD player with the old USB-I2S module I receive IR RC5 from a remote, send it as SPI to the FPGA, which forwards it over UART to the AVR32, which then sends it as HID to the computer. "We're not doing HID because it's easy, etc. etc." :-)