README.Debian (3249B)
1 alsa-utils README.Debian 2 ------------------------ 3 4 Contents 5 -------- 6 News 7 Restoring mixer levels 8 Storing mixer levels 9 Error messages 10 11 12 News 13 ---- 14 Last updated 12 April 2009 15 16 17 Restoring mixer levels 18 ---------------------- 19 ALSA drivers initialize hardware mixer levels to zero. It is usually 20 desirable to set things up so that the mixer levels for basic sound 21 output are automatically raised to reasonable levels after the drivers 22 have completed their initialization. 23 24 Currently, alsa-utils accomplishes this by having its initscript's 25 "start" method restore mixer levels to what they were the last time 26 they were saved (see below). The levels are stored in the file 27 /var/lib/alsa/asound.state. If either the latter file or the alsactl 28 program is not available then amixer is used to set mixer levels to 29 "reasonable" default values. 30 31 To set mixer levels to "reasonable" default values from the command 32 line (i.e., without trying first to restore saved values), run 33 "/etc/init.d/alsa-utils reset". 34 35 For modular drivers on a udev system, the /lib/alsa/udev script runs 36 the initscript "start" method after a driver has initialized and its 37 associated control device has been created. 38 39 For integral drivers and modular ones loaded very early in the boot 40 process, the initscript is configured to be run as part of runlevel 41 initialization. Restoration of mixer levels on bootup can be disabled 42 by configuring the alsa-utils "service" as stopped in runlevel S. On a 43 system that uses sysv-rc this means that you should RENAME 44 /etc/rcS.d/S50alsa-utils to /etc/rcS.d/K50alsa-utils. The symlink 45 should not be deleted---only renamed. 46 47 48 Storing mixer levels 49 ------------------------- 50 By default mixer levels are stored before shutdown by the initscript's 51 "stop" method. The initscript is run with "stop" in runleves 0 and 6. 52 53 To disable this behavior, if you are using sysv-rc, REMOVE the 54 "K50alsa-utils" symbolic links from /etc/rc0.d/ and /etc/rc6.d/. 55 The symlinks should be removed, not just renamed. 56 57 Note that this scheme is different from and simpler than the scheme 58 that was used by the "alsa" initscript when it contained the code 59 that implemented mixer level storing and restoring. The runlevels_save 60 environment variable is no longer used---indeed, there is no 61 /etc/default/ file for alsa-utils at all---and there is no longer a 62 choice of values for "alsactl_store_on_shutdown". Now "alsactl store" 63 is run on shutdown unconditionally; however, this can be disabled by 64 configuring the alsa-utils "service" as floating in runlevels 0 and 6, 65 as described above. 66 67 68 Error messages 69 -------------- 70 If the initscript "start" method is run early in the boot process, 71 before /usr/ is mounted, then it may print an error message. The 72 message can be ignored because the initscript gets run again later in 73 the boot process. 74 75 /etc/init.d/alsa-utils: Warning: No alsactl program available. 76 77 If you use the snd-cs46xx module then you may see messages like this: 78 79 Jan 26 14:32:50 foo kernel: ALSA ../../alsa-kernel/pci/cs46xx/cs46xx_lib.c:427: cs46xx: failure waiting for FIFO command to complete 80 81 This arises from a bug in the driver, but so far I have yet to 82 observe any consequent malfunction in the sound card.