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

[sc.dying%gmail.com@localhost]

The following reply was made to PR kern/55856; it has been noted by GNATS.

From: sc.dying%gmail.com@localhost
To: gnats-bugs%netbsd.org@localhost, kern-bug-people%netbsd.org@localhost,
 gnats-admin%netbsd.org@localhost, netbsd-bugs%netbsd.org@localhost, buhrow%nfbcal.org@localhost
Cc: 
Subject: Re: kern/55856: uaudio gets device timeout on C-Media USB sound
 device
Date: Sun, 18 Apr 2021 12:38:46 +0000

 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.