Module Name: src
Committed By: riastradh
Date: Sat Jun 12 12:11:01 UTC 2021
Modified Files:
src/sys/dev/usb: uhub.c
Log Message:
uhub(4): Allow only one explore/rescan at a time.
Otherwise we might simultaneously attach two autoconf instances of
the same device, which leads to no good.
To generate a diff of this commit:
cvs rdiff -u -r1.147 -r1.148 src/sys/dev/usb/uhub.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/uhub.c
diff -u src/sys/dev/usb/uhub.c:1.147 src/sys/dev/usb/uhub.c:1.148
--- src/sys/dev/usb/uhub.c:1.147 Fri Jun 5 17:20:56 2020
+++ src/sys/dev/usb/uhub.c Sat Jun 12 12:11:01 2021
@@ -1,4 +1,4 @@
-/* $NetBSD: uhub.c,v 1.147 2020/06/05 17:20:56 maxv Exp $ */
+/* $NetBSD: uhub.c,v 1.148 2021/06/12 12:11:01 riastradh Exp $ */
/* $FreeBSD: src/sys/dev/usb/uhub.c,v 1.18 1999/11/17 22:33:43 n_hibma Exp $ */
/* $OpenBSD: uhub.c,v 1.86 2015/06/29 18:27:40 mpi Exp $ */
@@ -37,7 +37,7 @@
*/
#include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: uhub.c,v 1.147 2020/06/05 17:20:56 maxv Exp $");
+__KERNEL_RCSID(0, "$NetBSD: uhub.c,v 1.148 2021/06/12 12:11:01 riastradh Exp $");
#ifdef _KERNEL_OPT
#include "opt_usb.h"
@@ -110,6 +110,7 @@ struct uhub_softc {
struct usbd_pipe *sc_ipipe; /* interrupt pipe */
kmutex_t sc_lock;
+ kcondvar_t sc_cv;
uint8_t *sc_statusbuf;
uint8_t *sc_statuspend;
@@ -118,6 +119,8 @@ struct uhub_softc {
bool sc_explorepending;
bool sc_first_explore;
bool sc_running;
+
+ struct lwp *sc_exploring;
};
#define UHUB_IS_HIGH_SPEED(sc) \
@@ -127,6 +130,8 @@ struct uhub_softc {
#define PORTSTAT_ISSET(sc, port) \
((sc)->sc_status[(port) / 8] & (1 << ((port) % 8)))
+Static usbd_status uhub_explore_enter(struct uhub_softc *);
+Static void uhub_explore_exit(struct uhub_softc *);
Static usbd_status uhub_explore(struct usbd_device *);
Static void uhub_intr(struct usbd_xfer *, void *, usbd_status);
@@ -365,6 +370,7 @@ uhub_attach(device_t parent, device_t se
sc->sc_statuspend = kmem_zalloc(sc->sc_statuslen, KM_SLEEP);
sc->sc_status = kmem_alloc(sc->sc_statuslen, KM_SLEEP);
mutex_init(&sc->sc_lock, MUTEX_DEFAULT, IPL_SOFTUSB);
+ cv_init(&sc->sc_cv, "uhubex");
/* force initial scan */
memset(sc->sc_status, 0xff, sc->sc_statuslen);
@@ -476,6 +482,41 @@ uhub_attach(device_t parent, device_t se
config_pending_decr(self);
}
+Static usbd_status
+uhub_explore_enter(struct uhub_softc *sc)
+{
+ usbd_status err;
+
+ mutex_enter(&sc->sc_lock);
+ for (;;) {
+ if (sc->sc_exploring == NULL) {
+ sc->sc_exploring = curlwp;
+ err = 0;
+ break;
+ }
+ KASSERT(sc->sc_exploring != curlwp);
+ if (cv_wait_sig(&sc->sc_cv, &sc->sc_lock)) {
+ err = USBD_INTERRUPTED;
+ break;
+ }
+ }
+ mutex_exit(&sc->sc_lock);
+
+ return err;
+}
+
+Static void
+uhub_explore_exit(struct uhub_softc *sc)
+{
+
+ mutex_enter(&sc->sc_lock);
+ KASSERTMSG(sc->sc_exploring == curlwp, "lwp %p exploring %s",
+ sc->sc_exploring, device_xname(sc->sc_dev));
+ sc->sc_exploring = NULL;
+ cv_broadcast(&sc->sc_cv);
+ mutex_exit(&sc->sc_lock);
+}
+
usbd_status
uhub_explore(struct usbd_device *dev)
{
@@ -499,6 +540,11 @@ uhub_explore(struct usbd_device *dev)
if (dev->ud_depth > USB_HUB_MAX_DEPTH)
return USBD_TOO_DEEP;
+ /* Only one explore at a time, please. */
+ err = uhub_explore_enter(sc);
+ if (err)
+ return err;
+
if (PORTSTAT_ISSET(sc, 0)) { /* hub status change */
usb_hub_status_t hs;
@@ -803,6 +849,7 @@ uhub_explore(struct usbd_device *dev)
}
}
mutex_exit(&sc->sc_lock);
+ uhub_explore_exit(sc);
if (sc->sc_first_explore) {
config_pending_decr(sc->sc_dev);
sc->sc_first_explore = false;
@@ -866,6 +913,7 @@ uhub_detach(device_t self, int flags)
if (sc->sc_statusbuf)
kmem_free(sc->sc_statusbuf, sc->sc_statuslen);
+ cv_destroy(&sc->sc_cv);
mutex_destroy(&sc->sc_lock);
/* XXXSMP usb */
@@ -882,12 +930,15 @@ uhub_rescan(device_t self, const char *i
struct usbd_device *dev;
int port;
+ if (uhub_explore_enter(sc) != 0)
+ return EBUSY;
for (port = 1; port <= hub->uh_hubdesc.bNbrPorts; port++) {
dev = hub->uh_ports[port - 1].up_dev;
if (dev == NULL)
continue;
usbd_reattach_device(sc->sc_dev, dev, port, locators);
}
+ uhub_explore_exit(sc);
return 0;
}
