[src/trunk]: src/sys/dev/usb Use callout_halt and usb_rem_task_wait on detach...

[riastradh <riastradh%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/681b25bf11e5
branches:  trunk
changeset: 991737:681b25bf11e5
user:      riastradh <riastradh%NetBSD.org@localhost>
date:      Sun Jul 29 02:00:17 2018 +0000

description:
Use callout_halt and usb_rem_task_wait on detach in aue(4).

diffstat:

 sys/dev/usb/if_aue.c |  17 ++++++++++-------
 1 files changed, 10 insertions(+), 7 deletions(-)

diffs (40 lines):

diff -r d458f6b2a5be -r 681b25bf11e5 sys/dev/usb/if_aue.c
--- a/sys/dev/usb/if_aue.c      Sun Jul 29 02:00:07 2018 +0000
+++ b/sys/dev/usb/if_aue.c      Sun Jul 29 02:00:17 2018 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: if_aue.c,v 1.143 2018/06/26 06:48:02 msaitoh Exp $     */
+/*     $NetBSD: if_aue.c,v 1.144 2018/07/29 02:00:17 riastradh Exp $   */
 
 /*
  * Copyright (c) 1997, 1998, 1999, 2000
@@ -78,7 +78,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: if_aue.c,v 1.143 2018/06/26 06:48:02 msaitoh Exp $");
+__KERNEL_RCSID(0, "$NetBSD: if_aue.c,v 1.144 2018/07/29 02:00:17 riastradh Exp $");
 
 #ifdef _KERNEL_OPT
 #include "opt_usb.h"
@@ -886,13 +886,16 @@
                return 0;
        }
 
-       callout_stop(&sc->aue_stat_ch);
        /*
-        * Remove any pending tasks.  They cannot be executing because they run
-        * in the same thread as detach.
+        * XXX Halting callout guarantees no more tick tasks.  What
+        * guarantees no more stop tasks?  What guarantees no more
+        * calls to aue_send?  Don't we need to wait for if_detach or
+        * something?  Should we set sc->aue_dying here?  Is device
+        * deactivation guaranteed to have already happened?
         */
-       usb_rem_task(sc->aue_udev, &sc->aue_tick_task);
-       usb_rem_task(sc->aue_udev, &sc->aue_stop_task);
+       callout_halt(&sc->aue_stat_ch, NULL);
+       usb_rem_task_wait(sc->aue_udev, &sc->aue_tick_task, USB_TASKQ_DRIVER);
+       usb_rem_task_wait(sc->aue_udev, &sc->aue_stop_task, USB_TASKQ_DRIVER);
 
        sc->aue_closing = 1;
        cv_signal(&sc->aue_domc);