#1960: Sound goes to the random card --------------------------------------------+------------------------------- Reporter: [EMAIL PROTECTED] | Owner: [email protected] Type: task | Status: new Priority: normal | Milestone: 6.2 Component: BOOK | Version: SVN Severity: normal | Resolution: Keywords: | --------------------------------------------+------------------------------- Old description:
> After the udev_update merge, the module loading order became random. If > someone has two sound cards and both drivers are modular, the "default" > sound card becomes random. I.e., after some boots, the FM801 card is > treated as the "default" one, and after rebooting it may well be that the > onboard SBPCI sound card becomes the default. So one cannot predict where > the sound goes. > > One cannot address this in LFS or BLFS by creating persistent symlinks, > because ALSA library doesn't allow specification of the output device via > device node name (i.e., one can create a persistent /dev/snd/pcmIntelD0 > symlink that always points to the right card, but cannot tell ALSA to > output sound using this symlink). > > I have already complained to LKML about that, and was told to use a > completely non-standard method for binding the default device to a > certain card: > > http://lkml.org/lkml/2006/1/5/214 > > So there are the following alternatives: > > 1) fix the card order in modprobe.conf: > > {{{ > options snd-fm801 index=0 > options snd-ens1371 index=1 > }}} > > 2) bind the default device to the correct card in /etc/asound.conf: > > {{{ > pcm.dsp0 { > type plug > slave.pcm "dmix:FM801AU" > } > }}} > > 3) Don't rely upon udev to load ALSA drivers, do that by hand in > /etc/sysconfig/modules so that the order becomes known and fixed. New description: After the udev_update merge, the module loading order became random. If someone has two sound cards and both drivers are modular, the "default" sound card becomes random. I.e., after some boots, the FM801 card is treated as the "default" one, and after rebooting it may well be that the onboard SBPCI sound card becomes the default. So one cannot predict where the sound goes. One cannot address this in LFS or BLFS by creating persistent symlinks, because ALSA library doesn't allow specification of the output device via device node name (i.e., one can create a persistent /dev/snd/pcmIntelD0 symlink that always points to the right card, but cannot tell ALSA to output sound using this symlink). I have already complained to LKML about that, and was told to use a completely non-standard method for binding the default device to a certain card: http://lkml.org/lkml/2006/1/5/214 So there are the following alternatives: 1) fix the card order in modprobe.conf: {{{ options snd-fm801 index=0 options snd-ens1371 index=1 }}} 2) bind the default device to the correct card in /etc/asound.conf: {{{ pcm.default { type plug slave.pcm "dmix:FM801AU" } }}} 3) Don't rely upon udev to load ALSA drivers, do that by hand in /etc/sysconfig/modules so that the order becomes known and fixed. Comment (by [EMAIL PROTECTED]): If drivers are non.modular, one can append {{{ snd-fm801.index=0 snd- ens1371.index=1 }}} to the kernel command line. So, I propose mentioning the problem in the book, and implementing option 1 and kernel command line trick as the easiest solutions. One more note: Debian duplicate of this bug was marked as wontfix: http://bugs.debian.org/365226 -- Ticket URL: <http://wiki.linuxfromscratch.org/blfs/ticket/1960> BLFS Trac <http://wiki.linuxfromscratch.org/blfs> Beyond Linux From Scratch -- http://linuxfromscratch.org/mailman/listinfo/blfs-book FAQ: http://www.linuxfromscratch.org/blfs/faq.html Unsubscribe: See the above information page
