freebsd-src/share
Christos Margiolis e8c0d15a64 sound: Get rid of snd_clone and use DEVFS_CDEVPRIV(9)
Currently the snd_clone framework creates device nodes on-demand for
every channel, through the dsp_clone() callback, and is responsible for
routing audio to the appropriate channel(s). This patch gets rid of the
whole snd_clone framework (including any related sysctls) and instead
uses DEVFS_CDEVPRIV(9) to handle device opening, channel allocation and
audio routing. This results in a significant reduction in code size as
well as complexity.

Behavior that is preserved:

- hw.snd.basename_clone.
- Exclusive access of an audio device (i.e VCHANs disabled).
- Multiple processes can read from/write to the device.
- A device can only be opened as many times as the maximum allowed
  channel number (see SND_MAXHWCHAN in pcm/sound.h).
- OSSv4 compatibility aliases are preserved.

Behavior changes:

Only one /dev/dspX device node is created (on attach) for each audio
device, as opposed to the current /dev/dspX.Y devices created by
snd_clone. According to the sound(4) man page, devices are not meant to
be opened through /dev/dspX.Y anyway, so it is best if we do not create
device nodes for them in the first place. As a result of this, modify
dsp_oss_audioinfo() to print /dev/dspX in the "ai->devnode", instead of
/dev/dspX.Y.

Sponsored by:	The FreeBSD Foundation
MFC after:	2 months
Reviewed by:	dev_submerge.ch, bapt, markj
Differential Revision:	https://reviews.freebsd.org/D44411
2024-04-11 20:06:30 +02:00
..
colldef Remove $FreeBSD$: one-line sh pattern 2023-08-16 11:55:03 -06:00
colldef_unicode Remove $FreeBSD$: one-line sh pattern 2023-08-16 11:55:03 -06:00
ctypedef Remove $FreeBSD$: one-line sh pattern 2023-08-16 11:55:03 -06:00
dict share: Remove ancient SCCS tags. 2023-11-26 22:23:29 -07:00
doc Grammar fix in share/doc/IPv6/IMPLEMENTATION 2024-02-13 15:16:01 +08:00
dtrace libdtrace: decode all tcp header flags and add 2023-12-31 15:02:03 +01:00
examples share/examples/sound: Fix spelling "controller" 2024-02-13 14:18:04 +08:00
i18n Remove $FreeBSD$: one-line sh pattern 2023-08-16 11:55:03 -06:00
keys Remove $FreeBSD$: one-line sh pattern 2023-08-16 11:55:03 -06:00
man sound: Get rid of snd_clone and use DEVFS_CDEVPRIV(9) 2024-04-11 20:06:30 +02:00
misc Add OpenBSD 7.5 to bsd-family-tree 2024-04-05 15:33:48 +02:00
mk config.mk: Add MK_VIMAGE knob 2024-04-09 13:05:56 -04:00
monetdef Remove $FreeBSD$: one-line sh pattern 2023-08-16 11:55:03 -06:00
monetdef_unicode Remove $FreeBSD$: one-line sh pattern 2023-08-16 11:55:03 -06:00
msgdef msgdef: fix NO and SI locales 2023-09-21 12:54:21 +02:00
msgdef_unicode Remove $FreeBSD$: one-line sh pattern 2023-08-16 11:55:03 -06:00
numericdef Remove $FreeBSD$: one-line sh pattern 2023-08-16 11:55:03 -06:00
numericdef_unicode Remove $FreeBSD$: one-line sh pattern 2023-08-16 11:55:03 -06:00
security Remove $FreeBSD$: one-line sh pattern 2023-08-16 11:55:03 -06:00
sendmail Remove $FreeBSD$: one-line sh pattern 2023-08-16 11:55:03 -06:00
skel dot.profile: handle symlinked $HOME 2024-02-13 13:24:22 -05:00
snmp Remove $FreeBSD$: two-line lua tag 2023-08-16 11:55:30 -06:00
syscons Remove $FreeBSD$: one-line sh pattern 2023-08-16 11:55:03 -06:00
tabset share: Remove ancient SCCS tags. 2023-11-26 22:23:29 -07:00
termcap share: Remove ancient SCCS tags. 2023-11-26 22:23:29 -07:00
tests Remove $FreeBSD$: one-line sh pattern 2023-08-16 11:55:03 -06:00
timedef Remove $FreeBSD$: one-line sh pattern 2023-08-16 11:55:03 -06:00
vt Trim various $FreeBSD$ 2023-10-10 10:34:43 -07:00
zoneinfo Fix share/zoneinfo for DIRDEPS_BUILD 2023-11-20 12:52:43 -08:00
Makefile share: Remove ancient SCCS tags. 2023-11-26 22:23:29 -07:00
Makefile.inc share: Remove ancient SCCS tags. 2023-11-26 22:23:29 -07:00