Hi, I've suffered a harddrive failure and am having to reconfigure parts I deemed too uncritical to back up, including my asoundrc (that'll teach me). The first part of that was getting dmix+dsnoop working on my soundcard, so I'm starting with this: pcm.!default { type plug slave { pcm "hwm" rate 48000 format S32_LE } } pcm.hw_capture { type dsnoop ipc_key 1000 slave { pcm "hw:DG,0" format S32_LE rate 48000 } } pcm.hw_playback { type dmix ipc_key 1001 slave { pcm "hw:DG,0" format S32_LE rate 48000 } } pcm.hwm { type asym playback.pcm "hw_playback" capture.pcm "hw_capture" } Further information on my system: 64-bit Gentoo running a 4.0.5 kernel, with alsa-lib version 1.0.29. The following commands all work individually, omitting the common parameters "-f S32_LE -r 48000 -c 2": arecord -D hw:DG,0 arecord -D plug:hw_capture arecord -D plug:hwm aplay -D hw:DG,0 aplay -D plug:hw_playback aplay -D plug:hwm It's also possible to combine them like this (either with pipes, or using separate in-/outputs): arecord -D plug:hw_capture | aplay -D hw:DG,0 arecord -D hw:DG,0 | aplay -D plug:hw_playback If I however start them on hw_capture/hw_playback at the same time, I get an error from the second process, either from aplay/dmix: alsa-lib-1.0.29/src/pcm/pcm_dmix.c:1095:(snd_pcm_dmix_open) unable to initialize sum ring buffer or from arecord/dsnoop: alsa-lib-1.0.29/src/pcm/pcm_dsnoop.c:596:(snd_pcm_dsnoop_open) unable to create IPC shm instance So there seems to be something screwy going on with the shared memory stuff happening there. strace on aplay shows the following shm calls just before it prints the error: shmget(0x33ea, 144000, IPC_CREAT|0600) = -1 EINVAL (Invalid argument) shmget(0x33ea, 0, 0600) = 9830417 shmctl(9830417, IPC_STAT, 0x7ffdea3c81b0) = 0 and on arecord it shows these: semget(0x33ea, 1, IPC_CREAT|0600) = 5996545 semop(5996545, {{0, 0, 0}, {0, 1, SEM_UNDO}}, 2) = 0 shmget(0x33ea, 488, IPC_CREAT|0600) = 10027026 shmat(10027026, 0, 0) = 0x7f4369890000 mlock(0x7f4369890000, 488) = 0 shmctl(10027026, IPC_STAT, 0x7ffd12287da0) = 0 shmdt(0x7f4369890000) = 0 shmctl(10027026, IPC_STAT, 0x7ffd12287d10) = 0 My first guess was that I had the ipc_keys configured incorrectly, but they're different, so that shouldn't be it. /dev/shm also shows a bunch of files owned by my user, so generally that should be working as well. If anybody has any suggestions on how to proceed they'd be greatly appreciated. :) Cheers, --Valentin ------------------------------------------------------------------------------ _______________________________________________ Alsa-user mailing list Alsa-user@xxxxxxxxxxxxxxxxxxxxx https://lists.sourceforge.net/lists/listinfo/alsa-user