# ALSA soundcard-configuration
config SND_TIMER
tristate
config SND_PCM
tristate
select SND_TIMER if SND_PCM_TIMER
config SND_PCM_ELD
bool
config SND_PCM_IEC958
bool
config SND_DMAENGINE_PCM
tristate
config SND_HWDEP
tristate
config SND_RAWMIDI
tristate
config SND_COMPRESS_OFFLOAD
tristate
# To be effective this also requires INPUT - users should say:
# select SND_JACK if INPUT=y || INPUT=SND
# to avoid having to force INPUT on.
config SND_JACK
bool
config SND_SEQUENCER
tristate "Sequencer support"
select SND_TIMER
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.
config SND_SEQ_DUMMY
tristate "Sequencer dummy client"
depends on SND_SEQUENCER
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_OSSEMUL
select SOUND_OSS_CORE
bool
config SND_MIXER_OSS
tristate "OSS Mixer API"
select SND_OSSEMUL
help
To enable OSS mixer API emulation (/dev/mixer*), say Y here
and read <file:Documentation/sound/alsa/OSS-Emulation.txt>.
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-mixer-oss.
config SND_PCM_OSS
tristate "OSS PCM (digital audio) API"
select SND_OSSEMUL
select SND_PCM
help
To enable OSS digital audio (PCM) emulation (/dev/dsp*), say Y
here and read <file:Documentation/sound/alsa/OSS-Emulation.txt>.
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-pcm-oss.
config SND_PCM_OSS_PLUGINS
bool "OSS PCM (digital audio) API - Include plugin system"
depends on SND_PCM_OSS
default y
help
If you disable this option, the ALSA's OSS PCM API will not
support conversion of channels, formats and rates. It will
behave like most of new OSS/Free drivers in 2.4/2.6 kernels.
config SND_PCM_TIMER
bool "PCM timer interface" if EXPERT
default y
help
If you disable this option, pcm timer will be inavailable, so
those stubs used pcm timer (e.g. dmix, dsnoop & co) may work
incorrectlly.
For some embedded device, we may disable it to reduce memory
footprint, about 20KB on x86_64 platform.
config SND_SEQUENCER_OSS
bool "OSS Sequencer API"
depends on SND_SEQUENCER
select SND_OSSEMUL
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.
If you choose M in "Sequencer support" (SND_SEQUENCER),
this will be compiled as a module. The module will be called
snd-seq-oss.
config SND_HRTIMER
tristate "HR-timer backend support"
depends on HIGH_RES_TIMERS
select SND_TIMER
help
Say Y here to enable HR-timer backend for ALSA timer. ALSA uses
the hrtimer as a precise timing source. The ALSA sequencer code
also can use this timing source.
To compile this driver as a module, choose M here: the module
will be called snd-hrtimer.
config SND_SEQ_HRTIMER_DEFAULT
bool "Use HR-timer as default sequencer timer"
depends on SND_HRTIMER && SND_SEQUENCER
default y
help
Say Y here to use the HR-timer backend as the default sequencer
timer.
config SND_RTCTIMER
tristate "RTC Timer support"
depends on RTC
select SND_TIMER
help
Say Y here to enable RTC timer support for ALSA. ALSA uses
the RTC timer as a precise timing source and maps the RTC
timer to ALSA's timer interface. The ALSA sequencer code also
can use this timing source.
To compile this driver as a module, choose M here: the module
will be called snd-rtctimer.
Note that this option is exclusive with the new RTC drivers
(CONFIG_RTC_CLASS) since this requires the old API.
config SND_SEQ_RTCTIMER_DEFAULT
bool "Use RTC as default sequencer timer"
depends on SND_RTCTIMER && SND_SEQUENCER
depends on !SND_SEQ_HRTIMER_DEFAULT
default y
help
Say Y here to use the RTC timer as the default sequencer
timer. This is strongly recommended because it ensures
precise MIDI timing even when the system timer runs at less
than 1000 Hz.
If in doubt, say Y.
config SND_DYNAMIC_MINORS
bool "Dynamic device file minor numbers"
help
If you say Y here, the minor numbers of ALSA device files in
/dev/snd/ are allocated dynamically. This allows you to have
more than 8 sound cards, but requires a dynamic device file
system like udev.
If you are unsure about this, say N here.
config SND_MAX_CARDS
int "Max number of sound cards"
range 4 256
default 32
depends on SND_DYNAMIC_MINORS
help
Specify the max number of sound cards that can be assigned
on a single machine.
config SND_SUPPORT_OLD_API
bool "Support old ALSA API"
default y
help
Say Y here to support the obsolete ALSA PCM API (ver.0.9.0 rc3
or older).
config SND_PROC_FS
bool "Sound Proc FS Support" if EXPERT
depends on PROC_FS
default y
help
Say 'N' to disable Sound proc FS, which may reduce code size about
9KB on x86_64 platform.
If unsure say Y.
config SND_VERBOSE_PROCFS
bool "Verbose procfs contents"
depends on SND_PROC_FS
default y
help
Say Y here to include code for verbose procfs contents (provides
useful information to developers when a problem occurs). On the
other side, it makes the ALSA subsystem larger.
config SND_VERBOSE_PRINTK
bool "Verbose printk"
help
Say Y here to enable verbose log messages. These messages
will help to identify source file and position containing
printed messages.
You don't need this unless you're debugging ALSA.
config SND_DEBUG
bool "Debug"
help
Say Y here to enable ALSA debug code.
config SND_DEBUG_VERBOSE
bool "More verbose debug"
depends on SND_DEBUG
help
Say Y here to enable extra-verbose debugging messages.
Let me repeat: it enables EXTRA-VERBOSE DEBUGGING messages.
So, say Y only if you are ready to be annoyed.
config SND_PCM_XRUN_DEBUG
bool "Enable PCM ring buffer overrun/underrun debugging"
default n
depends on SND_DEBUG && SND_VERBOSE_PROCFS
help
Say Y to enable the PCM ring buffer overrun/underrun debugging.
It is usually not required, but if you have trouble with
sound clicking when system is loaded, it may help to determine
the process or driver which causes the scheduling gaps.
config SND_VMASTER
bool
config SND_DMA_SGBUF
def_bool y
depends on X86
source "sound/core/seq/Kconfig"