Module Name: src
Committed By: riastradh
Date: Thu Mar 3 05:50:47 UTC 2022
Modified Files:
src/sys/dev/usb: usbnet.c
Log Message:
usbnet: Omit needless locking around usbnet_isdying.
Now that is tested and set with atomic_load/store, there is no need
to hold the lock -- which means we can set it while the core lock is
held during, e.g., a reset sequence, and use that to interrupt the
sequence so it doesn't get stuck waiting to time out when the device
is physically removed.
To generate a diff of this commit:
cvs rdiff -u -r1.73 -r1.74 src/sys/dev/usb/usbnet.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/usb/usbnet.c
diff -u src/sys/dev/usb/usbnet.c:1.73 src/sys/dev/usb/usbnet.c:1.74
--- src/sys/dev/usb/usbnet.c:1.73 Thu Mar 3 05:50:39 2022
+++ src/sys/dev/usb/usbnet.c Thu Mar 3 05:50:47 2022
@@ -1,4 +1,4 @@
-/* $NetBSD: usbnet.c,v 1.73 2022/03/03 05:50:39 riastradh Exp $ */
+/* $NetBSD: usbnet.c,v 1.74 2022/03/03 05:50:47 riastradh Exp $ */
/*
* Copyright (c) 2019 Matthew R. Green
@@ -31,7 +31,7 @@
*/
#include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: usbnet.c,v 1.73 2022/03/03 05:50:39 riastradh Exp $");
+__KERNEL_RCSID(0, "$NetBSD: usbnet.c,v 1.74 2022/03/03 05:50:47 riastradh Exp $");
#include <sys/param.h>
#include <sys/kernel.h>
@@ -1075,12 +1075,11 @@ usbnet_mcast_task(void *arg)
{
USBNETHIST_FUNC();
struct usbnet * const un = arg;
- struct usbnet_private * const unp = un->un_pri;
struct ifnet * const ifp = usbnet_ifp(un);
- bool dying;
struct ifreq ifr;
- USBNETHIST_CALLARGSN(10, "%jd: enter", unp->unp_number, 0, 0, 0);
+ USBNETHIST_CALLARGSN(10, "%jd: enter",
+ un->un_pri->unp_number, 0, 0, 0);
/*
* If we're detaching, we must check usbnet_isdying _before_
@@ -1091,10 +1090,7 @@ usbnet_mcast_task(void *arg)
* issuing if_detach, and necessary, so that we don't touch
* IFNET_LOCK after if_detach. See usbnet_detach for details.
*/
- mutex_enter(&unp->unp_core_lock);
- dying = usbnet_isdying(un);
- mutex_exit(&unp->unp_core_lock);
- if (dying)
+ if (usbnet_isdying(un))
return;
/*
@@ -1288,7 +1284,6 @@ usbnet_if_init(struct ifnet *ifp)
{
USBNETHIST_FUNC(); USBNETHIST_CALLED();
struct usbnet * const un = ifp->if_softc;
- bool dying;
int error;
KASSERTMSG(IFNET_LOCKED(ifp), "%s", ifp->if_xname);
@@ -1297,10 +1292,7 @@ usbnet_if_init(struct ifnet *ifp)
* Prevent anyone from bringing the interface back up once
* we're detaching.
*/
- mutex_enter(&un->un_pri->unp_core_lock);
- dying = usbnet_isdying(un);
- mutex_exit(&un->un_pri->unp_core_lock);
- if (dying)
+ if (usbnet_isdying(un))
return EIO;
mutex_enter(&un->un_pri->unp_core_lock);
@@ -1591,9 +1583,7 @@ usbnet_detach(device_t self, int flags)
* Prevent new activity. After we stop the interface, it
* cannot be brought back up.
*/
- mutex_enter(&unp->unp_core_lock);
atomic_store_relaxed(&unp->unp_dying, true);
- mutex_exit(&unp->unp_core_lock);
/*
* If we're still running on the network, stop and wait for all
@@ -1720,9 +1710,7 @@ usbnet_activate(device_t self, devact_t
case DVACT_DEACTIVATE:
if_deactivate(ifp);
- mutex_enter(&unp->unp_core_lock);
atomic_store_relaxed(&unp->unp_dying, true);
- mutex_exit(&unp->unp_core_lock);
mutex_enter(&unp->unp_rxlock);
mutex_enter(&unp->unp_txlock);
