The branch main has been updated by christos:
URL:
https://cgit.FreeBSD.org/src/commit/?id=fd906e47b18f53b09524647bf8431dc6170b8dfd
commit fd906e47b18f53b09524647bf8431dc6170b8dfd
Author: Christos Margiolis <chris...@freebsd.org>
AuthorDate: 2025-02-25 11:44:24 +0000
Commit: Christos Margiolis <chris...@freebsd.org>
CommitDate: 2025-02-25 11:44:24 +0000
sound: Simplify locking during device creation
The mechanism of acquiring SD_F_BUSY in pcm_init() and releasing it in
pcm_register() is a leftover from the previous device creation scheme,
where pcm_init() (previously pcm_register()) would create the sysctl
nodes, as well as the device node. In this scenario, acquiring SD_F_BUSY
was necessary, in order to avoid races in case the device was accessed
before it was ready for use. Commit 66f3eb14e955 ("sound: Move sysctl
and /dev/dspX creation to pcm_setstatus()") fixed this issue, so we can
simplify things now. Only acquire SD_F_BUSY in pcm_addchan(), because
chn_init() expects to be called with SD_F_BUSY acquired.
While here, move the sndstat_register() call further down to be more
robust.
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Reviewed by: markj
Differential Revision: https://reviews.freebsd.org/D48482
---
sys/dev/sound/pcm/sound.c | 17 +++++------------
1 file changed, 5 insertions(+), 12 deletions(-)
diff --git a/sys/dev/sound/pcm/sound.c b/sys/dev/sound/pcm/sound.c
index c0934dde7718..3e76626f5c57 100644
--- a/sys/dev/sound/pcm/sound.c
+++ b/sys/dev/sound/pcm/sound.c
@@ -136,9 +136,9 @@ pcm_addchan(device_t dev, int dir, kobj_class_t cls, void
*devinfo)
struct snddev_info *d = device_get_softc(dev);
struct pcm_channel *ch;
- PCM_BUSYASSERT(d);
-
PCM_LOCK(d);
+ PCM_WAIT(d);
+ PCM_ACQUIRE(d);
ch = chn_init(d, NULL, cls, dir, devinfo);
if (!ch) {
device_printf(d->dev, "chn_init(%s, %d, %p) failed\n",
@@ -146,6 +146,7 @@ pcm_addchan(device_t dev, int dir, kobj_class_t cls, void
*devinfo)
PCM_UNLOCK(d);
return (ENODEV);
}
+ PCM_RELEASE(d);
PCM_UNLOCK(d);
return (0);
@@ -388,7 +389,6 @@ pcm_init(device_t dev, void *devinfo)
d->dev = dev;
d->lock = snd_mtxcreate(device_get_nameunit(dev), "sound cdev");
cv_init(&d->cv, device_get_nameunit(dev));
- PCM_ACQUIRE_QUICK(d);
i = 0;
if (resource_int_value(device_get_name(dev), device_get_unit(dev),
@@ -428,8 +428,6 @@ pcm_register(device_t dev, char *str)
if (d->flags & SD_F_REGISTERED)
return (EINVAL);
- PCM_BUSYASSERT(d);
-
if (d->playcount == 0 || d->reccount == 0)
d->flags |= SD_F_SIMPLEX;
@@ -442,17 +440,10 @@ pcm_register(device_t dev, char *str)
d->flags |= SD_F_RVCHANS;
strlcpy(d->status, str, SND_STATUSLEN);
- sndstat_register(dev, d->status);
-
- PCM_LOCK(d);
/* Done, we're ready.. */
d->flags |= SD_F_REGISTERED;
- PCM_RELEASE(d);
-
- PCM_UNLOCK(d);
-
/*
* Create all sysctls once SD_F_REGISTERED is set else
* tunable sysctls won't work:
@@ -466,6 +457,8 @@ pcm_register(device_t dev, char *str)
else if (snd_unit_auto == 1)
snd_unit = pcm_best_unit(snd_unit);
+ sndstat_register(dev, d->status);
+
return (dsp_make_dev(dev));
}
