Is anything being done re: the pcm timeout issue?

Conrad J. Sabatier conrads at
Tue Aug 10 04:30:10 PDT 2004

On 10-Aug-2004 Rusty Nejdl wrote:
> Conrad J. Sabatier said:
>> No, no vchans in use here.  My main audio app is madplay, which I
>> run from a little "jukebox" script I wrote to play my MP3s.
> Ok, I've looked a bit at madplay and it looks like sound is very
> different in 5.3-current.  (Yes, I know about the device change in
> the kernel).  I haven't had a chance to test this out yet in 5.3
> because I've been focusing on some other issues - mainly GIANT's
> which are killing performance for me in 5.2.
> I'm going to load this up on my laptop tomorrow and see if I can
> cause this to break in any conceivable way for me.  I have a dual
> opteron system I can play with in my lab, but I'm afraid that this
> one doesn't have sound on it.

Cool, thanks.

>> I've been unable to determine what's triggering the breakage myself.
>> The script runs fine for a while, selecting random MP3 files and
>> running madplay to play them one by one.  Suddenly, madplay will
>> output the message "output: write failed" (or something like that)
>> and my system log will show "pcm0:play:0: play interrupt timeout,
>> channel dead".
>> After that, any further attempts to play a sound file of any sort
>> result in only a split-second of sound followed by the same messages
>> as above. The only cure is a reboot.
>> I posted some truss output from madplay a while back, but it's
>> probably not very useful, since a timeout had already occurred in
>> a previous run, so the listing only showed what was happening once
>> the device had already become broken.
>> Catching it "in the act", so to speak, is tricky, as it may work
>> fine for an hour or two before the first breakage occurs.  This
>> would require a HUGE amount of truss or ktrace logging.
>> We had a discussion recently here about certain peculiarities in the
>> sound code, but never reached any useful conclusions, and none of
>> our sound experts ever joined in, either.
> Yeah, I noticed that too.  Wasn't sure though, since I just recently
> joined the list.
>> I would hate to see 5.3 released with this problem still unsolved,
>> but it's beginning to look like that may, in fact, be the case,
>> unfortunately.  I had hoped, too, that by this time we would have
>> seen the new MIDI code incorporated into the tree as well, but it
>> seems that sound (other than the abrupt yanking of the previous
>> MIDI code and the recent renaming of devices/drivers) is being sadly
>> neglected lately.
> Well, let's get testing and breaking, then.

I'm with you!  If there's anything I can do, feel free to ask away.


Conrad J. Sabatier <conrads at> -- "In Unix veritas"

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