At Mon, 20 Oct 2003 11:05:29 -0700, Steve deRosier wrote: > > All, > > We've noticed a problem with the newest version of Alsa while doing some > stress testing of our devices. Basically, the scenerio is we're playing > through a large library of .ogg files over the weekend. When we checked > on the progress upon getting in on Monday, we discovered that the PCM > had ceased playing, and our ogg player had started a ton of instances > (one for each song it was supposed to play) and couldn't play on any of > them. Looking at /proc/asound/card0/pcm0p/sub0/status: > # cat status > state: OPEN > trigger_time: 642.000000000 > tstamp : -1071072720.-1071072332 > delay : 498 > avail : -1072507698 > avail_max : -1071072720
when the state is OPEN, these values are bogus, since snd_pcm_status() returns immediately without putting the values. > ----- > hw_ptr : 26942906 > appl_ptr : 26942906 they are real values. i can't remember any reason of the restriction above. i think it's ok to remove it. > It seems that our ogg player is set to blocking behavior and each one is > blocked on the call to open the pcm. The intrieging thing is the > timestamp is negative. It jumped out that this just looks wrong! > > Hypothesis 1: After a really long time playing, the timestamp on the > pcm wraps to negative. alsa can't handle this and blocks on the output. > It's no longer running, but is still in an OPEN state so nothing else > can open it. alsa should either use an unsigned value so large that it > is impossable to overflow (???), use an unsigned and detect overflow and > handle it gracefully, or use a signed value and detect the overflow/wrap > and handle it. > Hypothesis 2: We're barking up the wrong tree and the only thing wrong > is that the proc entry is formmated poorly. (but even if that is the > case, the problem still happens where after prolonged time alsa stops us). at least, the values above make no sense. which version of ALSA driver are you using? Takashi ------------------------------------------------------- This SF.net email is sponsored by OSDN developer relations Here's your chance to show off your extensive product knowledge We want to know what you know. Tell us and you have a chance to win $100 http://www.zoomerang.com/survey.zgi?HRPT1X3RYQNC5V4MLNSV3E54 _______________________________________________ Alsa-devel mailing list [EMAIL PROTECTED] https://lists.sourceforge.net/lists/listinfo/alsa-devel
