On Fri, Mar 09, 2007 at 05:38:34PM +0100, Takashi Iwai wrote: > At Thu, 8 Mar 2007 21:51:28 +0000, > John Rigg wrote: > > > > On Thu, Mar 08, 2007 at 07:58:23PM +0100, Takashi Iwai wrote: > > > At Thu, 08 Mar 2007 18:16:02 +0100, > > > Simon Lewis wrote: > > > > Many JACK users have successfully used the following patch: > > > > > > > > http://www.sound-man.co.uk/linuxaudio/pcm_multi-patch > > > > > > Well, the patch is no real fix. It's likely a workaround for JACK, > > > though. Someone has to take time to track down this bug more deeply. > > > > True, the patch is just a workaround for JACK. However, I would > > argue that most users of pcm_multi are probably JACK users. > > No, multi plugin is used in many surround PCM definitions as default. > It's pretty hidden, but multi streams are no rare case. I hadn't noticed that. Thanks for pointing it out (and thank you for looking at this problem!) > > Surely adding code that breaks something for the majority of users (no > > matter how correct that code is in isolation) is not a good thing. > > Sure. However, this code addition was for bugfixes of major other use > cases like above, IIRC. The regression should be avoided and should > be fixed. But the point is, we (at least, I) haven't been enough > informed, unfortunately (or simply burried in a big TODO list :) > > Now, let's back to the original problem: Could someone give a pointer > describing for this problem, or just explain a bit details here? > I vaguely remember but not precisely at all now... > I'm willing to dig down after knowing how I can reproduce the bug. To summarise, using multiple sound cards with pcm_multi and jackd no longer works in duplex mode ever since extra linking code was added to pcm_multi.c in alsa-lib-1.0.9rc1. Trying to start jackd in duplex fails with a poll timeout message. It still works in playback-only or capture-only modes. The lack of duplex operation makes overdubbing in a recording studio, for example, impossible. A configuration which produces the problem with two ice1712 cards set up as a 16 channel multi device is shown here: http://www.sound-man.co.uk/linuxaudio/ice1712multi.html With the .asoundrc described in the above link the following command fails with a poll timeout message: jackd -d alsa -P multi_playback -C multi_capture The following still work: jackd -d alsa -P multi_playback jackd -d alsa -C multi_capture John ------------------------------------------------------------------------- Take Surveys. Earn Cash. Influence the Future of IT Join SourceForge.net's Techsay panel and you'll get the chance to share your opinions on IT & business topics through brief surveys-and earn cash http://www.techsay.com/default.php?page=join.php&p=sourceforge&CID=DEVDEV _______________________________________________ Alsa-devel mailing list Alsa-devel@xxxxxxxxxxxxxxxxxxxxx https://lists.sourceforge.net/lists/listinfo/alsa-devel
