CVS commit: src/sys/dev/usb

[matthew green]

Module Name:    src
Committed By:   mrg
Date:           Mon Sep  9 07:20:16 UTC 2019

Modified Files:
        src/sys/dev/usb: usbnet.c usbnet.h

Log Message:
document usbnet_private locking.  minor knf.


To generate a diff of this commit:
cvs rdiff -u -r1.27 -r1.28 src/sys/dev/usb/usbnet.c
cvs rdiff -u -r1.14 -r1.15 src/sys/dev/usb/usbnet.h

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:1.27 src/sys/dev/usb/usbnet.c:1.28
--- src/sys/dev/usb/usbnet.c:1.27	Sun Sep  8 19:00:33 2019
+++ src/sys/dev/usb/usbnet.c	Mon Sep  9 07:20:16 2019
@@ -1,4 +1,4 @@
-/*	$NetBSD: usbnet.c,v 1.27 2019/09/08 19:00:33 mrg Exp $	*/
+/*	$NetBSD: usbnet.c,v 1.28 2019/09/09 07:20:16 mrg Exp $	*/
 
 /*
  * Copyright (c) 2019 Matthew R. Green
@@ -33,7 +33,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: usbnet.c,v 1.27 2019/09/08 19:00:33 mrg Exp $");
+__KERNEL_RCSID(0, "$NetBSD: usbnet.c,v 1.28 2019/09/09 07:20:16 mrg Exp $");
 
 #include <sys/param.h>
 #include <sys/kernel.h>
@@ -59,6 +59,11 @@ struct usbnet_private {
 	 * - unp_rxlock protects the rx path and its data
 	 * - unp_txlock protects the tx path and its data
 	 * - unp_detachcv handles detach vs open references
+	 *
+	 * the lock ordering is:
+	 *	ifnet lock -> unp_lock -> unp_rxlock -> unp_txlock
+	 *      unp_lock -> unp_miilock
+	 * and unp_lock may be dropped after taking unp_miilock.
 	 */
 	kmutex_t		unp_lock;
 	kmutex_t		unp_miilock;

Index: src/sys/dev/usb/usbnet.h
diff -u src/sys/dev/usb/usbnet.h:1.14 src/sys/dev/usb/usbnet.h:1.15
--- src/sys/dev/usb/usbnet.h:1.14	Fri Aug 23 04:32:57 2019
+++ src/sys/dev/usb/usbnet.h	Mon Sep  9 07:20:16 2019
@@ -1,4 +1,4 @@
-/*	$NetBSD: usbnet.h,v 1.14 2019/08/23 04:32:57 mrg Exp $	*/
+/*	$NetBSD: usbnet.h,v 1.15 2019/09/09 07:20:16 mrg Exp $	*/
 
 /*
  * Copyright (c) 2019 Matthew R. Green
@@ -343,7 +343,8 @@ void	usbnet_input(struct usbnet * const,
 
 /* autoconf */
 void	usbnet_attach(struct usbnet *un, const char *);
-void	usbnet_attach_ifp(struct usbnet *, unsigned, unsigned, const struct usbnet_mii *);
+void	usbnet_attach_ifp(struct usbnet *, unsigned, unsigned,
+			  const struct usbnet_mii *);
 int	usbnet_detach(device_t, int);
 int	usbnet_activate(device_t, devact_t);