git: 532b45fe103c - main - sound: Create a dsp_close() helper function

The branch main has been updated by christos:

URL: https://cgit.FreeBSD.org/src/commit/?id=532b45fe103c623855bf1004d5de2fd41e2885e4

commit 532b45fe103c623855bf1004d5de2fd41e2885e4
Author:     Christos Margiolis <christos@FreeBSD.org>
AuthorDate: 2025-04-25 16:56:03 +0000
Commit:     Christos Margiolis <christos@FreeBSD.org>
CommitDate: 2025-04-25 16:56:22 +0000

    sound: Create a dsp_close() helper function
    
    Sponsored by:   The FreeBSD Foundation
    MFC after:      1 week
    Reviewed by:    kib, markj
    Differential Revision:  https://reviews.freebsd.org/D49805
---
 sys/dev/sound/pcm/dsp.c | 129 +++++++++++++++++++++---------------------------
 1 file changed, 55 insertions(+), 74 deletions(-)

diff --git a/sys/dev/sound/pcm/dsp.c b/sys/dev/sound/pcm/dsp.c
index bc64b50b4510..0f7cf0d456cf 100644
--- a/sys/dev/sound/pcm/dsp.c
+++ b/sys/dev/sound/pcm/dsp.c
@@ -97,6 +97,7 @@ struct cdevsw dsp_cdevsw = {
 
 static eventhandler_tag dsp_ehtag = NULL;
 
+static void dsp_close_chan(struct pcm_channel *c);
 static int dsp_oss_syncgroup(struct pcm_channel *wrch, struct pcm_channel *rdch, oss_syncgroup *group);
 static int dsp_oss_syncstart(int sg_id);
 static int dsp_oss_policy(struct pcm_channel *wrch, struct pcm_channel *rdch, int policy);
@@ -241,20 +242,19 @@ dsp_chn_alloc(struct snddev_info *d, struct pcm_channel **ch, int direction,
 }
 
 static void
-dsp_close(void *data)
+dsp_close_chan(struct pcm_channel *c)
 {
-	struct dsp_cdevpriv *priv = data;
-	struct pcm_channel *rdch, *wrch, *parent;
 	struct snddev_info *d;
+	struct pcm_channel *parent;
 	int sg_ids;
 
-	if (priv == NULL)
+	if (c == NULL)
 		return;
 
-	d = priv->sc;
+	d = c->parentsnddev;
 	/* At this point pcm_unregister() will destroy all channels anyway. */
 	if (!DSP_REGISTERED(d))
-		goto skip;
+		return;
 
 	PCM_GIANT_ENTER(d);
 
@@ -262,82 +262,63 @@ dsp_close(void *data)
 	PCM_WAIT(d);
 	PCM_ACQUIRE(d);
 
-	rdch = priv->rdch;
-	wrch = priv->wrch;
+	CHN_REMOVE(d, c, channels.pcm.opened);
 
-	if (rdch != NULL)
-		CHN_REMOVE(d, rdch, channels.pcm.opened);
-	if (wrch != NULL)
-		CHN_REMOVE(d, wrch, channels.pcm.opened);
+	PCM_UNLOCK(d);
 
-	if (rdch != NULL || wrch != NULL) {
-		PCM_UNLOCK(d);
-		if (rdch != NULL) {
-			/*
-			 * The channel itself need not be locked because:
-			 *   a)  Adding a channel to a syncgroup happens only
-			 *       in dsp_ioctl(), which cannot run concurrently
-			 *       to dsp_close().
-			 *   b)  The syncmember pointer (sm) is protected by
-			 *       the global syncgroup list lock.
-			 *   c)  A channel can't just disappear, invalidating
-			 *       pointers, unless it's closed/dereferenced
-			 *       first.
-			 */
-			PCM_SG_LOCK();
-			sg_ids = chn_syncdestroy(rdch);
-			PCM_SG_UNLOCK();
-			if (sg_ids != 0)
-				free_unr(pcmsg_unrhdr, sg_ids);
-
-			if (rdch->flags & CHN_F_VIRTUAL) {
-				parent = rdch->parentchannel;
-				CHN_LOCK(parent);
-				CHN_LOCK(rdch);
-				vchan_destroy(rdch);
-				CHN_UNLOCK(parent);
-			} else {
-				CHN_LOCK(rdch);
-				chn_abort(rdch); /* won't sleep */
-				rdch->flags &= ~(CHN_F_RUNNING | CHN_F_MMAP |
-				    CHN_F_DEAD | CHN_F_EXCLUSIVE);
-				chn_reset(rdch, 0, 0);
-				chn_release(rdch);
-			}
-		}
-		if (wrch != NULL) {
-			/*
-			 * Please see block above.
-			 */
-			PCM_SG_LOCK();
-			sg_ids = chn_syncdestroy(wrch);
-			PCM_SG_UNLOCK();
-			if (sg_ids != 0)
-				free_unr(pcmsg_unrhdr, sg_ids);
-
-			if (wrch->flags & CHN_F_VIRTUAL) {
-				parent = wrch->parentchannel;
-				CHN_LOCK(parent);
-				CHN_LOCK(wrch);
-				vchan_destroy(wrch);
-				CHN_UNLOCK(parent);
-			} else {
-				CHN_LOCK(wrch);
-				chn_flush(wrch); /* may sleep */
-				wrch->flags &= ~(CHN_F_RUNNING | CHN_F_MMAP |
-				    CHN_F_DEAD | CHN_F_EXCLUSIVE);
-				chn_reset(wrch, 0, 0);
-				chn_release(wrch);
-			}
-		}
-		PCM_LOCK(d);
+	/*
+	 * The channel itself need not be locked because:
+	 *   a)  Adding a channel to a syncgroup happens only in dsp_ioctl(),
+	 *       which cannot run concurrently to dsp_close_chan().
+	 *   b)  The syncmember pointer (sm) is protected by the global
+	 *       syncgroup list lock.
+	 *   c)  A channel can't just disappear, invalidating pointers, unless
+	 *       it's closed/dereferenced first.
+	 */
+	PCM_SG_LOCK();
+	sg_ids = chn_syncdestroy(c);
+	PCM_SG_UNLOCK();
+	if (sg_ids != 0)
+		free_unr(pcmsg_unrhdr, sg_ids);
+
+	if (c->flags & CHN_F_VIRTUAL) {
+		parent = c->parentchannel;
+		CHN_LOCK(parent);
+		CHN_LOCK(c);
+		vchan_destroy(c);
+		CHN_UNLOCK(parent);
+	} else {
+		CHN_LOCK(c);
+		if (c->direction == PCMDIR_REC)
+			chn_abort(c); /* won't sleep */
+		else
+			chn_flush(c); /* may sleep */
+		c->flags &= ~(CHN_F_RUNNING | CHN_F_MMAP | CHN_F_DEAD |
+		    CHN_F_EXCLUSIVE);
+		chn_reset(c, 0, 0);
+		chn_release(c);
 	}
 
+	PCM_LOCK(d);
+
 	PCM_RELEASE(d);
 	PCM_UNLOCK(d);
 
 	PCM_GIANT_LEAVE(d);
-skip:
+}
+
+
+static void
+dsp_close(void *data)
+{
+	struct dsp_cdevpriv *priv = data;
+
+	if (priv == NULL)
+		return;
+
+	dsp_close_chan(priv->rdch);
+	dsp_close_chan(priv->wrch);
+
 	free(priv, M_DEVBUF);
 	priv = NULL;
 }