[src/netbsd-8]: src/sys/dev/usb Pull up following revision(s) (requested by s...

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

details:   https://anonhg.NetBSD.org/src/rev/d0a27d56d18d
branches:  netbsd-8
changeset: 933917:d0a27d56d18d
user:      martin <martin%NetBSD.org@localhost>
date:      Sun May 31 10:27:26 2020 +0000

description:
Pull up following revision(s) (requested by skrll in ticket #1551):

        sys/dev/usb/usb.c: revision 1.187

Don't allow open of /dev/usb if there are no attached busses.
PR kern/55303 mutex_vector_enter,512: uninitialized lock

diffstat:

 sys/dev/usb/usb.c |  15 +++++++++++++--
 1 files changed, 13 insertions(+), 2 deletions(-)

diffs (50 lines):

diff -r ccd74b6a363f -r d0a27d56d18d sys/dev/usb/usb.c
--- a/sys/dev/usb/usb.c Mon May 25 17:49:03 2020 +0000
+++ b/sys/dev/usb/usb.c Sun May 31 10:27:26 2020 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: usb.c,v 1.165.6.5 2019/11/16 16:30:09 martin Exp $     */
+/*     $NetBSD: usb.c,v 1.165.6.6 2020/05/31 10:27:26 martin Exp $     */
 
 /*
  * Copyright (c) 1998, 2002, 2008, 2012 The NetBSD Foundation, Inc.
@@ -37,7 +37,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: usb.c,v 1.165.6.5 2019/11/16 16:30:09 martin Exp $");
+__KERNEL_RCSID(0, "$NetBSD: usb.c,v 1.165.6.6 2020/05/31 10:27:26 martin Exp $");
 
 #ifdef _KERNEL_OPT
 #include "opt_usb.h"
@@ -179,6 +179,11 @@
 Static void    usb_event_thread(void *);
 Static void    usb_task_thread(void *);
 
+/*
+ * Count of USB busses
+ */
+int nusbbusses = 0;
+
 #define USB_MAX_EVENTS 100
 struct usb_event_q {
        struct usb_event ue;
@@ -331,6 +336,9 @@
 
        USBHIST_FUNC(); USBHIST_CALLED(usbdebug);
 
+       /* Protected by KERNEL_LOCK */
+       nusbbusses++;
+
        sc->sc_bus->ub_usbctl = self;
        sc->sc_port.up_power = USB_MAX_POWER;
 
@@ -639,6 +647,9 @@
        int unit = minor(dev);
        struct usb_softc *sc;
 
+       if (nusbbusses == 0)
+               return ENXIO;
+
        if (unit == USB_DEV_MINOR) {
                if (usb_dev_open)
                        return EBUSY;