svn commit: r231647 - head/sys/dev/sound/pcm

[Alexander Motin]

Author: mav
Date: Tue Feb 14 09:19:30 2012
New Revision: 231647
URL: http://svn.freebsd.org/changeset/base/231647

Log:
  Do not handle MOD_SHUTDOWN equally to MOD_UNLOAD in sound kernel module.
  MOD_SHUTDOWN is not an end of existence, and there is a life after it.
  In particular, code previously called on MOD_SHUTDOWN grabbed lock and
  deallocated unit numbering. That caused infinite wait loop if snd_uaudio
  tried to destroy its PCM device after that point.
  
  MFC after:	3 days

Modified:
  head/sys/dev/sound/pcm/sound.c

Modified: head/sys/dev/sound/pcm/sound.c
==============================================================================
--- head/sys/dev/sound/pcm/sound.c	Tue Feb 14 09:12:08 2012	(r231646)
+++ head/sys/dev/sound/pcm/sound.c	Tue Feb 14 09:19:30 2012	(r231647)
@@ -1415,7 +1415,6 @@ sound_modevent(module_t mod, int type, v
 			pcmsg_unrhdr = new_unrhdr(1, INT_MAX, NULL);
 			break;
 		case MOD_UNLOAD:
-		case MOD_SHUTDOWN:
 			ret = sndstat_acquire(curthread);
 			if (ret != 0)
 				break;
@@ -1424,6 +1423,8 @@ sound_modevent(module_t mod, int type, v
 				pcmsg_unrhdr = NULL;
 			}
 			break;
+		case MOD_SHUTDOWN:
+			break;
 		default:
 			ret = ENOTSUP;
 	}