[amd64] Sound breakage with snd_ich driver

[Don Lewis]

On 19 Jul, Conrad J. Sabatier wrote:
> This problem has persisted for the last several weeks now, close to a
> month or so, I would say.
> 
> Playing MP3s using madplay, everything works fine for a while, then
> suddenly I get an "output: write: Invalid argument" error each time
> madplay starts up.  Any further attempts to use sound via any method or
> app likewise fail.  Sound remains broken until a reboot.
> 
> Upgraded the system again yesterday, to the new "sound" drivers, same
> results.
> 
> I've attached truss output from one of these failed madplay runs.

I suspect that the sound driver is getting interrupt timeouts and is
marking the channel dead.  Do you see the following message in
/var/log/messages?
	 play interrupt timeout, channel dead
If so, I've seen other reports of this.

I think the chn_write() code needs some careful analysis ...