The branch main has been updated by christos:
URL:
https://cgit.FreeBSD.org/src/commit/?id=ab95710f30f7255d3a6be22a1a2c375ee0f96868
commit ab95710f30f7255d3a6be22a1a2c375ee0f96868
Author: Christos Margiolis <chris...@freebsd.org>
AuthorDate: 2025-03-10 20:47:39 +0000
Commit: Christos Margiolis <chris...@freebsd.org>
CommitDate: 2025-03-10 20:47:39 +0000
sound: Make dev.pcm.X.mode dynamic
Currently dev.pcm.X.mode is calculated only once in pcm_sysinit(), which
is called by pcm_register() during attach, but this can result in
inconsistencies.
For some context, what pcm_mode_init() does is, it checks if "playcount"
is positive, in which case we assume the device supports playback. The
same is done for "reccount" for recording, and if "mixer_dev" is not
NULL, we know the device has a mixer.
The "playcount" and "reccount" variables correspond to the number of
_primary_ playback/recording channels, so we can assume that the primary
channels have been created before reaching pcm_mode_init(). However, for
the mixer that's not always the case. If the mixer is created _after_
pcm_register(), as is the case for snd_dummy(4) for example,
pcm_mode_init() will see that "mixer_dev" is NULL, and report that the
device does not have a mixer, whereas in reality we just created it
afterwards.
While this could be fixed by simply creating the mixers always before
pcm_register(), it is better to be robust and calculate the mode
dynamically.
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Differential Revision: https://reviews.freebsd.org/D49024
---
sys/dev/sound/pcm/sound.c | 25 +++++++++++++++----------
1 file changed, 15 insertions(+), 10 deletions(-)
diff --git a/sys/dev/sound/pcm/sound.c b/sys/dev/sound/pcm/sound.c
index 5759c06725ce..c262a57ea5f1 100644
--- a/sys/dev/sound/pcm/sound.c
+++ b/sys/dev/sound/pcm/sound.c
@@ -322,28 +322,32 @@ sysctl_dev_pcm_bitperfect(SYSCTL_HANDLER_ARGS)
return (err);
}
-static u_int8_t
-pcm_mode_init(struct snddev_info *d)
+static int
+sysctl_dev_pcm_mode(SYSCTL_HANDLER_ARGS)
{
- u_int8_t mode = 0;
+ struct snddev_info *d;
+ int mode = 0;
+ d = oidp->oid_arg1;
+ if (!PCM_REGISTERED(d))
+ return (ENODEV);
+
+ PCM_LOCK(d);
if (d->playcount > 0)
mode |= PCM_MODE_PLAY;
if (d->reccount > 0)
mode |= PCM_MODE_REC;
if (d->mixer_dev != NULL)
mode |= PCM_MODE_MIXER;
+ PCM_UNLOCK(d);
- return (mode);
+ return (sysctl_handle_int(oidp, &mode, 0, req));
}
static void
pcm_sysinit(device_t dev)
{
struct snddev_info *d = device_get_softc(dev);
- u_int8_t mode;
-
- mode = pcm_mode_init(d);
sysctl_ctx_init(&d->play_sysctl_ctx);
d->play_sysctl_tree = SYSCTL_ADD_NODE(&d->play_sysctl_ctx,
@@ -364,9 +368,10 @@ pcm_sysinit(device_t dev)
"bitperfect", CTLTYPE_INT | CTLFLAG_RWTUN | CTLFLAG_MPSAFE, d,
sizeof(d), sysctl_dev_pcm_bitperfect, "I",
"bit-perfect playback/recording (0=disable, 1=enable)");
- SYSCTL_ADD_UINT(device_get_sysctl_ctx(dev),
- SYSCTL_CHILDREN(device_get_sysctl_tree(dev)),
- OID_AUTO, "mode", CTLFLAG_RD, NULL, mode,
+ SYSCTL_ADD_PROC(device_get_sysctl_ctx(dev),
+ SYSCTL_CHILDREN(device_get_sysctl_tree(dev)), OID_AUTO,
+ "mode", CTLTYPE_INT | CTLFLAG_RD | CTLFLAG_MPSAFE, d, sizeof(d),
+ sysctl_dev_pcm_mode, "I",
"mode (1=mixer, 2=play, 4=rec. The values are OR'ed if more than "
"one mode is supported)");
vchan_initsys(dev);
