Re: kern/55856: uaudio gets device timeout on C-Media USB sound device

[sc.dying%gmail.com@localhost]

On 2021/01/12 18:10, Brian Buhrow wrote:
> The following reply was made to PR kern/55856; it has been noted by GNATS.
> 
> From: Brian Buhrow <buhrow%nfbcal.org@localhost>
> To: gnats-bugs%netbsd.org@localhost
> Cc: buhrow%nfbcal.org@localhost
> Subject: Re: kern/55856: uaudio gets device timeout on C-Media USB sound device
> Date: Tue, 12 Jan 2021 10:06:27 -0800
> 
>  	hello.  Here's some more data on this issue.  The problem appears to be specific to the
>  xhci(4) driver.  Specifically, if I boot an older machine with NetBSD-9.1 with an uchi(4) USB
>  chip in it, the uaudio driver works fine with the C-Media USB audio device.  Of course, it's
>  also an I386 machine, not an amd64 machine but I hope that isn't the difference that
>  demonstrates the problem.  
>  So, I will now investigate potential issues with the xhci(4) driver.
>  -thanks
>  -Brian

AFAIK xhci(4) on NetBSD-9 does not support isochronous transfer
used in such as uaudio and uvideo.