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authorMartin Pieuchot <mpi@cvs.openbsd.org>2014-05-28 11:20:56 +0000
committerMartin Pieuchot <mpi@cvs.openbsd.org>2014-05-28 11:20:56 +0000
commit731c0ec0ed91f0b2eddc8427271f66a7a3acd676 (patch)
treec464bfab4037e0adb93f27fda94b1ef03f4df340 /sys/dev/usb
parent211c0627e50a1e0a8246b5736462b52cd4721d56 (diff)
Apart from the early exploration done to find a console keyboard during
the boot process, USB devices must be attached or detached from the usb task thread in order to avoid races with periodical explorations issued by uhub(4) interrupts. Respect this rule when detaching root hubs during a suspend/resume cycle and avoid some hangs due to the aforementioned race. Tested by Mattieu Baptiste, thanks!
Diffstat (limited to 'sys/dev/usb')
-rw-r--r--sys/dev/usb/uhub.c5
-rw-r--r--sys/dev/usb/usb.c36
-rw-r--r--sys/dev/usb/usbdivar.h3
3 files changed, 27 insertions, 17 deletions
diff --git a/sys/dev/usb/uhub.c b/sys/dev/usb/uhub.c
index 2ef5e6f8d9e..b5974247a7f 100644
--- a/sys/dev/usb/uhub.c
+++ b/sys/dev/usb/uhub.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: uhub.c,v 1.66 2014/03/11 10:24:42 mpi Exp $ */
+/* $OpenBSD: uhub.c,v 1.67 2014/05/28 11:20:55 mpi Exp $ */
/* $NetBSD: uhub.c,v 1.64 2003/02/08 03:32:51 ichiro Exp $ */
/* $FreeBSD: src/sys/dev/usb/uhub.c,v 1.18 1999/11/17 22:33:43 n_hibma Exp $ */
@@ -546,6 +546,9 @@ uhub_intr(struct usbd_xfer *xfer, void *addr, usbd_status status)
{
struct uhub_softc *sc = addr;
+ if (usbd_is_dying(sc->sc_hub))
+ return;
+
DPRINTF("%s: intr status=%d\n", sc->sc_dev.dv_xname, status);
if (status == USBD_STALLED)
usbd_clear_endpoint_stall_async(sc->sc_ipipe);
diff --git a/sys/dev/usb/usb.c b/sys/dev/usb/usb.c
index ff5c3b3d2a5..2397a2f308f 100644
--- a/sys/dev/usb/usb.c
+++ b/sys/dev/usb/usb.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: usb.c,v 1.96 2014/05/11 16:33:21 mpi Exp $ */
+/* $OpenBSD: usb.c,v 1.97 2014/05/28 11:20:55 mpi Exp $ */
/* $NetBSD: usb.c,v 1.77 2003/01/01 00:10:26 thorpej Exp $ */
/*
@@ -260,11 +260,15 @@ usb_attach_roothub(struct usb_softc *sc)
void
usb_detach_roothub(struct usb_softc *sc)
{
- /* Make all devices disconnect. */
- if (sc->sc_port.device != NULL)
- usb_disconnect_port(&sc->sc_port, (struct device *)sc);
+ /*
+ * To avoid races with the usb task thread, mark the root hub
+ * as disconnecting and schedule an exploration task to detach
+ * it.
+ */
+ sc->sc_bus->flags |= USB_BUS_DISCONNECTING;
+ usb_needs_explore(sc->sc_bus->root_hub, 0);
- usb_rem_wait_task(sc->sc_bus->root_hub, &sc->sc_explore_task);
+ usb_wait_task(sc->sc_bus->root_hub, &sc->sc_explore_task);
sc->sc_bus->root_hub = NULL;
}
@@ -840,7 +844,18 @@ usb_explore(void *v)
usb_delay_ms(sc->sc_bus, pwrdly - waited_ms);
}
- sc->sc_bus->root_hub->hub->explore(sc->sc_bus->root_hub);
+ if (sc->sc_bus->flags & USB_BUS_DISCONNECTING) {
+ /* Prevent new tasks from being scheduled. */
+ sc->sc_bus->dying = 1;
+
+ /* Make all devices disconnect. */
+ if (sc->sc_port.device != NULL)
+ usb_disconnect_port(&sc->sc_port, (struct device *)sc);
+
+ sc->sc_bus->flags &= ~USB_BUS_DISCONNECTING;
+ } else {
+ sc->sc_bus->root_hub->hub->explore(sc->sc_bus->root_hub);
+ }
if (sc->sc_bus->flags & USB_BUS_CONFIG_PENDING) {
DPRINTF(("%s: %s: first explore done\n", __func__,
@@ -896,7 +911,6 @@ usb_activate(struct device *self, int act)
switch (act) {
case DVACT_QUIESCE:
- sc->sc_bus->dying = 1;
if (sc->sc_bus->root_hub != NULL)
usb_detach_roothub(sc);
break;
@@ -914,10 +928,6 @@ usb_activate(struct device *self, int act)
usb_needs_explore(sc->sc_bus->root_hub, 0);
sc->sc_bus->use_polling--;
break;
- case DVACT_DEACTIVATE:
- rv = config_activate_children(self, act);
- sc->sc_bus->dying = 1;
- break;
default:
rv = config_activate_children(self, act);
break;
@@ -930,10 +940,6 @@ usb_detach(struct device *self, int flags)
{
struct usb_softc *sc = (struct usb_softc *)self;
- DPRINTF(("usb_detach: start\n"));
-
- sc->sc_bus->dying = 1;
-
if (sc->sc_bus->root_hub != NULL) {
usb_detach_roothub(sc);
diff --git a/sys/dev/usb/usbdivar.h b/sys/dev/usb/usbdivar.h
index ab2b9742e83..7cbeaafbe53 100644
--- a/sys/dev/usb/usbdivar.h
+++ b/sys/dev/usb/usbdivar.h
@@ -1,4 +1,4 @@
-/* $OpenBSD: usbdivar.h,v 1.58 2014/03/29 18:09:31 guenther Exp $ */
+/* $OpenBSD: usbdivar.h,v 1.59 2014/05/28 11:20:55 mpi Exp $ */
/* $NetBSD: usbdivar.h,v 1.70 2002/07/11 21:14:36 augustss Exp $ */
/* $FreeBSD: src/sys/dev/usb/usbdivar.h,v 1.11 1999/11/17 22:33:51 n_hibma Exp $ */
@@ -105,6 +105,7 @@ struct usbd_bus {
char dying;
int flags;
#define USB_BUS_CONFIG_PENDING 0x01
+#define USB_BUS_DISCONNECTING 0x02
struct device *usbctl;
struct usb_device_stats stats;
int intr_context;