• Takashi Iwai's avatar
    ALSA: seq: Allow the modular sequencer registration · 111b0cdb
    Takashi Iwai authored
    Many drivers bind the sequencer stuff in off-load by another driver
    module, so that it's loaded only on demand.  In the current code, this
    mechanism doesn't work when the driver is built-in while the sequencer
    is module.  We check with IS_REACHABLE() and enable only when the
    sequencer is in the same level of build.
    
    However, this is basically a overshoot.  The binder code
    (snd-seq-device) is an individual module from the sequencer core
    (snd-seq), and we just have to make the former a built-in while
    keeping the latter a module for allowing the scenario like the above.
    
    This patch achieves that by rewriting Kconfig slightly.  Now, a driver
    that provides the manual sequencer device binding should select
    CONFIG_SND_SEQ_DEVICE in a way as
    	select SND_SEQ_DEVICE if SND_SEQUENCER != n
    
    Note that the "!=n" is needed here to avoid the influence of the
    sequencer core is module while the driver is built-in.
    
    Also, since rawmidi.o may be linked with snd_seq_device.o when
    built-in, we have to shuffle the code to make the linker happy.
    (the kernel linker isn't smart enough yet to handle such a case.)
    That is, snd_seq_device.c is moved to sound/core from sound/core/seq,
    as well as Makefile.
    
    Last but not least, the patch replaces the code using IS_REACHABLE()
    with IS_ENABLED(), since now the condition meets always when enabled.
    Signed-off-by: default avatarTakashi Iwai <tiwai@suse.de>
    111b0cdb
Kconfig 25.3 KB