Module Name: src
Committed By: isaki
Date: Tue Feb 9 05:53:14 UTC 2021
Modified Files:
src/sys/dev/audio: audio.c
Log Message:
Change the lock conditions to call audio_unlink().
This can remove a different copy of audio_exlock_enter() in audio_unlink()
and can use normal one. Also, in audiodetach(), this can set the exlock
at more natual order (before calling audio_unlink()).
No noticeable functional changes are intended.
Thanks for comments, riastradh@.
To generate a diff of this commit:
cvs rdiff -u -r1.88 -r1.89 src/sys/dev/audio/audio.c
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
Modified files:
Index: src/sys/dev/audio/audio.c
diff -u src/sys/dev/audio/audio.c:1.88 src/sys/dev/audio/audio.c:1.89
--- src/sys/dev/audio/audio.c:1.88 Fri Jan 15 05:34:49 2021
+++ src/sys/dev/audio/audio.c Tue Feb 9 05:53:14 2021
@@ -1,4 +1,4 @@
-/* $NetBSD: audio.c,v 1.88 2021/01/15 05:34:49 isaki Exp $ */
+/* $NetBSD: audio.c,v 1.89 2021/02/09 05:53:14 isaki Exp $ */
/*-
* Copyright (c) 2008 The NetBSD Foundation, Inc.
@@ -138,7 +138,7 @@
*/
#include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: audio.c,v 1.88 2021/01/15 05:34:49 isaki Exp $");
+__KERNEL_RCSID(0, "$NetBSD: audio.c,v 1.89 2021/02/09 05:53:14 isaki Exp $");
#ifdef _KERNEL_OPT
#include "audio.h"
@@ -1334,9 +1334,10 @@ audiodetach(device_t self, int flags)
* that hold sc, and any new calls with files that were for sc will
* fail. Thus, we now have exclusive access to the softc.
*/
+ sc->sc_exlock = 1;
/*
- * Nuke all open instances.
+ * Clean up all open instances.
* Here, we no longer need any locks to traverse sc_files.
*/
while ((file = SLIST_FIRST(&sc->sc_files)) != NULL) {
@@ -1359,7 +1360,6 @@ audiodetach(device_t self, int flags)
pmf_device_deregister(self);
/* Free resources */
- sc->sc_exlock = 1;
if (sc->sc_pmixer) {
audio_mixer_destroy(sc, sc->sc_pmixer);
kmem_free(sc->sc_pmixer, sizeof(*sc->sc_pmixer));
@@ -2396,6 +2396,7 @@ bad:
int
audio_close(struct audio_softc *sc, audio_file_t *file)
{
+ int error;
/* Protect entering new fileops to this file */
atomic_store_relaxed(&file->dying, true);
@@ -2410,12 +2411,27 @@ audio_close(struct audio_softc *sc, audi
mutex_exit(sc->sc_lock);
}
- return audio_unlink(sc, file);
+ error = audio_exlock_enter(sc);
+ if (error) {
+ /*
+ * If EIO, this sc is about to detach. In this case, even if
+ * we don't do subsequent _unlink(), audiodetach() will do it.
+ */
+ if (error == EIO)
+ return error;
+
+ /* XXX This should not happen but what should I do ? */
+ panic("%s: can't acquire exlock: errno=%d", __func__, error);
+ }
+ error = audio_unlink(sc, file);
+ audio_exlock_exit(sc);
+
+ return error;
}
/*
* Unlink this file, but not freeing memory here.
- * Must be called without sc_lock nor sc_exlock held.
+ * Must be called with sc_exlock held and without sc_lock held.
*/
int
audio_unlink(struct audio_softc *sc, audio_file_t *file)
@@ -2432,25 +2448,6 @@ audio_unlink(struct audio_softc *sc, aud
"sc->sc_popens=%d, sc->sc_ropens=%d",
sc->sc_popens, sc->sc_ropens);
- /*
- * Acquire exlock to protect counters.
- * audio_exlock_enter() cannot be used here because we have to go
- * forward even if sc_dying is set.
- */
- while (__predict_false(sc->sc_exlock != 0)) {
- error = cv_timedwait_sig(&sc->sc_exlockcv, sc->sc_lock,
- mstohz(AUDIO_TIMEOUT));
- /* XXX what should I do on error? */
- if (error == EWOULDBLOCK) {
- mutex_exit(sc->sc_lock);
- audio_printf(sc,
- "%s: cv_timedwait_sig failed: errno=%d\n",
- __func__, error);
- return error;
- }
- }
- sc->sc_exlock = 1;
-
device_active(sc->sc_dev, DVA_SYSTEM);
mutex_enter(sc->sc_intr_lock);
@@ -2517,7 +2514,6 @@ audio_unlink(struct audio_softc *sc, aud
kauth_cred_free(sc->sc_cred);
TRACE(3, "done");
- audio_exlock_exit(sc);
return 0;
}
