Implement a detaching flag for the sound(4) subsystem to take

appropriate actions when we are trying to detach an audio device,
but cannot because someone is using it.

This avoids applications having to wait for the DSP read data
timeout before they receive any error indication.
Tested with virtual_oss(8).

Remove some unused definitions while at it.

PR:		194727
MFC after:	1 week
Sponsored by:	Mellanox Technologies

4 files changed, 20 insertions, 21 deletions

diff --git a/sys/dev/sound/pcm/dsp.c b/sys/dev/sound/pcm/dsp.c
index 99fcf8a16dbb..885b05aed1ad 100644
--- a/sys/dev/sound/pcm/dsp.c
+++ b/sys/dev/sound/pcm/dsp.c
@@ -460,7 +460,7 @@ dsp_open(struct cdev *i_dev, int flags, int mode, struct thread *td)
 		return (ENODEV);
 
 	d = dsp_get_info(i_dev);
-	if (!PCM_REGISTERED(d))
+	if (PCM_DETACHING(d) || !PCM_REGISTERED(d))
 		return (EBADF);
 
 	PCM_GIANT_ENTER(d);
@@ -830,7 +830,7 @@ dsp_io_ops(struct cdev *i_dev, struct uio *buf)
 	    ("%s(): io train wreck!", __func__));
 
 	d = dsp_get_info(i_dev);
-	if (!DSP_REGISTERED(d, i_dev))
+	if (PCM_DETACHING(d) || !DSP_REGISTERED(d, i_dev))
 		return (EBADF);
 
 	PCM_GIANT_ENTER(d);
@@ -1075,7 +1075,7 @@ dsp_ioctl(struct cdev *i_dev, u_long cmd, caddr_t arg, int mode,
 	int *arg_i, ret, tmp;
 
 	d = dsp_get_info(i_dev);
-	if (!DSP_REGISTERED(d, i_dev))
+	if (PCM_DETACHING(d) || !DSP_REGISTERED(d, i_dev))
 		return (EBADF);
 
 	PCM_GIANT_ENTER(d);
@@ -2170,9 +2170,11 @@ dsp_poll(struct cdev *i_dev, int events, struct thread *td)
 	int ret, e;
 
 	d = dsp_get_info(i_dev);
-	if (!DSP_REGISTERED(d, i_dev))
-		return (EBADF);
-
+	if (PCM_DETACHING(d) || !DSP_REGISTERED(d, i_dev)) {
+		/* XXX many clients don't understand POLLNVAL */
+		return (events & (POLLHUP | POLLPRI | POLLIN |
+		    POLLRDNORM | POLLOUT | POLLWRNORM));
+	}
 	PCM_GIANT_ENTER(d);
 
 	wrch = NULL;
@@ -2246,7 +2248,7 @@ dsp_mmap_single(struct cdev *i_dev, vm_ooffset_t *offset,
 		return (EINVAL);
 
 	d = dsp_get_info(i_dev);
-	if (!DSP_REGISTERED(d, i_dev))
+	if (PCM_DETACHING(d) || !DSP_REGISTERED(d, i_dev))
 		return (EINVAL);
 
 	PCM_GIANT_ENTER(d);
diff --git a/sys/dev/sound/pcm/mixer.c b/sys/dev/sound/pcm/mixer.c
index c58988758b62..5bc27d653552 100644
--- a/sys/dev/sound/pcm/mixer.c
+++ b/sys/dev/sound/pcm/mixer.c
@@ -153,7 +153,7 @@ mixer_set_softpcmvol(struct snd_mixer *m, struct snddev_info *d,
 	struct pcm_channel *c;
 	int dropmtx, acquiremtx;
 
-	if (!PCM_REGISTERED(d))
+	if (PCM_DETACHING(d) || !PCM_REGISTERED(d))
 		return (EINVAL);
 
 	if (mtx_owned(m->lock))
@@ -206,7 +206,7 @@ mixer_set_eq(struct snd_mixer *m, struct snddev_info *d,
 	else
 		return (EINVAL);
 
-	if (!PCM_REGISTERED(d))
+	if (PCM_DETACHING(d) || !PCM_REGISTERED(d))
 		return (EINVAL);
 
 	if (mtx_owned(m->lock))
@@ -1046,7 +1046,7 @@ mixer_open(struct cdev *i_dev, int flags, int mode, struct thread *td)
 
 	m = i_dev->si_drv1;
 	d = device_get_softc(m->dev);
-	if (!PCM_REGISTERED(d))
+	if (PCM_DETACHING(d) || !PCM_REGISTERED(d))
 		return (EBADF);
 
 	/* XXX Need Giant magic entry ??? */
@@ -1202,7 +1202,7 @@ mixer_ioctl(struct cdev *i_dev, u_long cmd, caddr_t arg, int mode,
 		return (EBADF);
 
 	d = device_get_softc(((struct snd_mixer *)i_dev->si_drv1)->dev);
-	if (!PCM_REGISTERED(d))
+	if (PCM_DETACHING(d) || !PCM_REGISTERED(d))
 		return (EBADF);
 
 	PCM_GIANT_ENTER(d);
@@ -1411,7 +1411,7 @@ mixer_oss_mixerinfo(struct cdev *i_dev, oss_mixerinfo *mi)
 	for (i = 0; pcm_devclass != NULL &&
 	    i < devclass_get_maxunit(pcm_devclass); i++) {
 		d = devclass_get_softc(pcm_devclass, i);
-		if (!PCM_REGISTERED(d))
+		if (PCM_DETACHING(d) || !PCM_REGISTERED(d))
 			continue;
 
 		/* XXX Need Giant magic entry */
diff --git a/sys/dev/sound/pcm/sound.c b/sys/dev/sound/pcm/sound.c
index bd3b4c684365..601474190d10 100644
--- a/sys/dev/sound/pcm/sound.c
+++ b/sys/dev/sound/pcm/sound.c
@@ -1162,6 +1162,8 @@ pcm_unregister(device_t dev)
 	PCM_LOCK(d);
 	PCM_WAIT(d);
 
+	d->flags |= SD_F_DETACHING;
+	
 	if (d->inprog != 0) {
 		device_printf(dev, "unregister: operation in progress\n");
 		PCM_UNLOCK(d);
diff --git a/sys/dev/sound/pcm/sound.h b/sys/dev/sound/pcm/sound.h
index 829ffcf6b721..5730e7fa39aa 100644
--- a/sys/dev/sound/pcm/sound.h
+++ b/sys/dev/sound/pcm/sound.h
@@ -131,15 +131,8 @@ struct snd_mixer;
 #define SD_F_SIMPLEX		0x00000001
 #define SD_F_AUTOVCHAN		0x00000002
 #define SD_F_SOFTPCMVOL		0x00000004
-/*
- * Obsolete due to better matrixing
- */
-#if 0
-#define SD_F_PSWAPLR		0x00000008
-#define SD_F_RSWAPLR		0x00000010
-#endif
 #define SD_F_DYING		0x00000008
-#define SD_F_SUICIDE		0x00000010
+#define SD_F_DETACHING		0x00000010
 #define SD_F_BUSY		0x00000020
 #define SD_F_MPSAFE		0x00000040
 #define SD_F_REGISTERED		0x00000080
@@ -165,7 +158,7 @@ struct snd_mixer;
 				"\002AUTOVCHAN"				\
 				"\003SOFTPCMVOL"			\
 				"\004DYING"				\
-				"\005SUICIDE"				\
+				"\005DETACHING"				\
 				"\006BUSY"				\
 				"\007MPSAFE"				\
 				"\010REGISTERED"			\
@@ -184,6 +177,8 @@ struct snd_mixer;
 #define PCM_REGISTERED(x)	(PCM_ALIVE(x) &&			\
 				 ((x)->flags & SD_F_REGISTERED))
 
+#define	PCM_DETACHING(x)	((x)->flags & SD_F_DETACHING)
+
 /* many variables should be reduced to a range. Here define a macro */
 #define RANGE(var, low, high) (var) = \
 	(((var)<(low))? (low) : ((var)>(high))? (high) : (var))