git: e015e079f9db - stable/15 - sndctl(8): Modify vchans only on supported directions

From: Christos Margiolis <christos_at_FreeBSD.org>
Date: Sun, 26 Oct 2025 14:22:23 UTC
The branch stable/15 has been updated by christos:

URL: https://cgit.FreeBSD.org/src/commit/?id=e015e079f9db0e1762e4249bdc76abec93213abc

commit e015e079f9db0e1762e4249bdc76abec93213abc
Author:     Christos Margiolis <christos@FreeBSD.org>
AuthorDate: 2025-10-22 11:50:55 +0000
Commit:     Christos Margiolis <christos@FreeBSD.org>
CommitDate: 2025-10-26 14:22:11 +0000

    sndctl(8): Modify vchans only on supported directions
    
    Currently mod_play_vchans() and mod_rec_vchans() run unconditionally,
    even if the direction (playback, recording) is not supported by the
    device. This results in the "autoconv" (see mod_autoconv()) control
    failing when run on simplex devices, because we'll be trying to modify
    vchans on an unsupported direction.
    
    Test whether the direction is supported and silently move on if it
    isn't.
    
    Sponsored by:   The FreeBSD Foundation
    MFC after:      4 days
    Differential Revision:  https://reviews.freebsd.org/D53233
    
    (cherry picked from commit 70b34fbdbea13c006a724844caa53f59e0e53bd0)
---
 usr.sbin/sndctl/sndctl.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/usr.sbin/sndctl/sndctl.c b/usr.sbin/sndctl/sndctl.c
index 156c845481c5..6977f0ab0ebe 100644
--- a/usr.sbin/sndctl/sndctl.c
+++ b/usr.sbin/sndctl/sndctl.c
@@ -830,6 +830,8 @@ mod_play_vchans(struct snd_dev *dp, void *arg)
 
 	if (dp->from_user)
 		return (-1);
+	if (!dp->play.pchans)
+		return (0);
 
 	snprintf(buf, sizeof(buf), "dev.pcm.%d.play.vchans", dp->unit);
 
@@ -873,6 +875,8 @@ mod_rec_vchans(struct snd_dev *dp, void *arg)
 
 	if (dp->from_user)
 		return (-1);
+	if (!dp->rec.pchans)
+		return (0);
 
 	snprintf(buf, sizeof(buf), "dev.pcm.%d.rec.vchans", dp->unit);