alistair23-linux/sound/core/seq/Kconfig
Takashi Iwai 111b0cdb97 ALSA: seq: Allow the modular sequencer registration
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: Takashi Iwai <tiwai@suse.de>
2017-06-12 08:43:33 +02:00

63 lines
1.5 KiB
Plaintext

config SND_SEQUENCER
tristate "Sequencer support"
select SND_TIMER
select SND_SEQ_DEVICE
help
Say Y or M to enable MIDI sequencer and router support. This
feature allows routing and enqueueing of MIDI events. Events
can be processed at a given time.
Many programs require this feature, so you should enable it
unless you know what you're doing.
if SND_SEQUENCER
config SND_SEQ_DUMMY
tristate "Sequencer dummy client"
help
Say Y here to enable the dummy sequencer client. This client
is a simple MIDI-through client: all normal input events are
redirected to the output port immediately.
You don't need this unless you want to connect many MIDI
devices or applications together.
To compile this driver as a module, choose M here: the module
will be called snd-seq-dummy.
config SND_SEQUENCER_OSS
tristate "OSS Sequencer API"
depends on SND_OSSEMUL
select SND_SEQ_MIDI_EVENT
help
Say Y here to enable OSS sequencer emulation (both
/dev/sequencer and /dev/music interfaces).
Many programs still use the OSS API, so say Y.
To compile this driver as a module, choose M here: the module
will be called snd-seq-oss.
config SND_SEQ_HRTIMER_DEFAULT
bool "Use HR-timer as default sequencer timer"
depends on SND_HRTIMER
default y
help
Say Y here to use the HR-timer backend as the default sequencer
timer.
config SND_SEQ_MIDI_EVENT
def_tristate SND_RAWMIDI
config SND_SEQ_MIDI
tristate
select SND_SEQ_MIDI_EVENT
config SND_SEQ_MIDI_EMUL
tristate
config SND_SEQ_VIRMIDI
tristate
endif # SND_SEQUENCER