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    ALSA: support module on-demand loading for seq and timer · 03cfe6f5
    Kay Sievers authored
    
    
    If CONFIG_SND_DYNAMIC_MINORS is used, assign /dev/snd/seq and
    /dev/snd/timer the usual static minors, and export specific
    module aliases to generate udev module on-demand loading
    instructions:
    
      $ cat /lib/modules/2.6.33.4-smp/modules.devname
      # Device nodes to trigger on-demand module loading.
      microcode cpu/microcode c10:184
      fuse fuse c10:229
      ppp_generic ppp c108:0
      tun net/tun c10:200
      uinput uinput c10:223
      dm_mod mapper/control c10:236
      snd_timer snd/timer c116:33
      snd_seq snd/seq c116:1
    
    The last two lines instruct udev to create device nodes, even
    when the modules are not loaded at that time.
    
    As soon as userspace accesses any of these nodes, the in-kernel
    module-loader will load the module, and the device can be used.
    
    The header file minor calculation needed to be simplified to
    make __stringify() (supports only two indirections) in
    the MODULE_ALIAS macro work.
    
    This is part of systemd's effort to get rid of unconditional
    module load instructions and needless init scripts.
    
    Cc: Lennart Poettering <lennart@poettering.net>
    Signed-off-by: default avatarKay Sievers <kay.sievers@vrfy.org>
    Signed-off-by: default avatarClemens Ladisch <clemens@ladisch.de>
    Signed-off-by: default avatarTakashi Iwai <tiwai@suse.de>
    03cfe6f5