I have an NDA with Tenor and am developing products with their devices so I have the latest code that runs on the evaluation cards.
Each manufacturer contracts with Tenor for customized firmware and you would need to contact Teac to see if they are going to support Linux.
As far as I know there is no public utility that will allow you to upgrade your firmware and you would need to return the device for a 'factory upgrade'.
I see. I just got it yesterday, so I am not too keen on sending it anywhere, if you understand
Maybe it would be easier to make a workaround for TE8802L in the Linux kernel instead, as I suppose the USB Audio Class 2 implementation in Linux is correct?
Can you explain what the bug/problem is with TE8802L?