The branch main has been updated by christos: URL: https://cgit.FreeBSD.org/src/commit/?id=9fb56421425fa35e56ce294284c08b09852052a5
commit 9fb56421425fa35e56ce294284c08b09852052a5 Author: Christos Margiolis <[email protected]> AuthorDate: 2026-05-21 12:22:38 +0000 Commit: Christos Margiolis <[email protected]> CommitDate: 2026-05-28 14:08:20 +0000 sound: Centralize and improve hot-swapping Introduce pcm_hotswap(), which is responsible for sending devctl SND/CONN notifications. There are two user-visible improvements with this patch: First, in pcm_unregister(), instead of just sending a SND/CONN/NODEV notification when all devices have detached, we also switch to the new default device if the previously default one has detached, but there are more left. Second, in pcm_register(), if the device happens to also be the new default device, we hot-swap to it. Additionally, if hw.snd.default_auto is set to 2, then we will essentially be hot-swapping to the newest attached device. The latter is especially useful for laptops like the Framework 16, which comes with a built-in snd_hda(4) speaker-microphone-only device, and headphones can work with the Framework Audio Expansion Card, which does not extend the snd_hda(4) device, but is in fact a separate snd_uaudio(4) device. To achieve automatic audio redirection between headphones and speakers in this case, there has to be a way to switch between different devices. The way the Audio Expansion Card works is by having snd_uaudio(4) attach to it when the headphones are plugged, and detach when unplugged, so this patch, along with hw.snd.default_auto=2, can pick up those attach events and switch automatically. Combined with the pcm_unregister() update, it becomes possible to switch back and forth between headphones and speakers. While here, be more robust and lock around snd_unit reads. In collaboration with: jrm Sponsored by: The FreeBSD Foundation MFC after: 1 week --- sys/dev/sound/pcm/sound.c | 47 ++++++++++++++++++++++++++++++++++++----------- 1 file changed, 36 insertions(+), 11 deletions(-) diff --git a/sys/dev/sound/pcm/sound.c b/sys/dev/sound/pcm/sound.c index d98952d7a984..235142eb5209 100644 --- a/sys/dev/sound/pcm/sound.c +++ b/sys/dev/sound/pcm/sound.c @@ -77,11 +77,30 @@ snd_setup_intr(device_t dev, struct resource *res, int flags, driver_intr_t hand return bus_setup_intr(dev, res, flags, NULL, hand, param, cookiep); } +static void +pcm_hotswap(void) +{ + struct snddev_info *d; + char buf[32]; + + bus_topo_assert(); + if (snd_unit >= 0) { + d = devclass_get_softc(pcm_devclass, snd_unit); + if (!PCM_REGISTERED(d)) + return; + snprintf(buf, sizeof(buf), "cdev=dsp%d", snd_unit); + if (d->reccount > 0) + devctl_notify("SND", "CONN", "IN", buf); + if (d->playcount > 0) + devctl_notify("SND", "CONN", "OUT", buf); + } else + devctl_notify("SND", "CONN", "NODEV", NULL); +} + static int sysctl_hw_snd_default_unit(SYSCTL_HANDLER_ARGS) { struct snddev_info *d; - char buf[32]; int error, unit; unit = snd_unit; @@ -95,13 +114,8 @@ sysctl_hw_snd_default_unit(SYSCTL_HANDLER_ARGS) } snd_unit = unit; snd_unit_auto = 0; + pcm_hotswap(); bus_topo_unlock(); - - snprintf(buf, sizeof(buf), "cdev=dsp%d", snd_unit); - if (d->reccount > 0) - devctl_notify("SND", "CONN", "IN", buf); - if (d->playcount > 0) - devctl_notify("SND", "CONN", "OUT", buf); } return (error); } @@ -373,6 +387,7 @@ int pcm_register(device_t dev, char *str) { struct snddev_info *d = device_get_softc(dev); + int err; /* should only be called once */ if (d->flags & SD_F_REGISTERED) @@ -417,6 +432,13 @@ pcm_register(device_t dev, char *str) vchan_initsys(dev); feeder_eq_initsys(dev); + sndstat_register(dev, SNDST_TYPE_PCM, d->status); + + err = dsp_make_dev(dev); + if (err) + return (err); + + bus_topo_lock(); if (snd_unit_auto < 0) snd_unit_auto = (snd_unit < 0) ? 1 : 0; if (snd_unit < 0 || snd_unit_auto > 1) @@ -424,9 +446,11 @@ pcm_register(device_t dev, char *str) else if (snd_unit_auto == 1) snd_unit = pcm_best_unit(snd_unit); - sndstat_register(dev, SNDST_TYPE_PCM, d->status); + if (snd_unit == device_get_unit(dev)) + pcm_hotswap(); + bus_topo_unlock(); - return (dsp_make_dev(dev)); + return (0); } int @@ -469,13 +493,14 @@ pcm_unregister(device_t dev) cv_destroy(&d->cv); mtx_destroy(&d->lock); + bus_topo_lock(); if (snd_unit == device_get_unit(dev)) { snd_unit = pcm_best_unit(-1); if (snd_unit_auto == 0) snd_unit_auto = 1; - if (snd_unit < 0) - devctl_notify("SND", "CONN", "NODEV", NULL); + pcm_hotswap(); } + bus_topo_unlock(); return (0); }
