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| author | hselasky <hselasky@FreeBSD.org> | 2014-06-11 05:39:08 +0000 |
|---|---|---|
| committer | hselasky <hselasky@FreeBSD.org> | 2014-06-11 05:39:08 +0000 |
| commit | 6976be81b3b183e75f2ecf2a0fe39136ace8cb9f (patch) | |
| tree | 48132ba6c7f1af2727c50cd208afbfc29b212dd5 /sys/dev/usb/controller/usb_controller.c | |
| parent | 150b18f93d81fc7c1cfeaaef8ccb23259a94e695 (diff) | |
| download | FreeBSD-src-6976be81b3b183e75f2ecf2a0fe39136ace8cb9f.zip FreeBSD-src-6976be81b3b183e75f2ecf2a0fe39136ace8cb9f.tar.gz | |
MFC r267240:
Resolve a deadlock setting the USB configuration index from userspace
on USB HUBs by moving the code into the USB explore threads. The
deadlock happens because child devices of the USB HUB don't have the
expected reference count when called from outside the explore
thread. Only the HUB device itself, which the IOCTL interface locks,
gets the correct reference count.
Diffstat (limited to 'sys/dev/usb/controller/usb_controller.c')
| -rw-r--r-- | sys/dev/usb/controller/usb_controller.c | 8 |
1 files changed, 7 insertions, 1 deletions
diff --git a/sys/dev/usb/controller/usb_controller.c b/sys/dev/usb/controller/usb_controller.c index d51719e..0464b3d 100644 --- a/sys/dev/usb/controller/usb_controller.c +++ b/sys/dev/usb/controller/usb_controller.c @@ -366,7 +366,13 @@ usb_bus_explore(struct usb_proc_msg *pm) if (bus->no_explore != 0) return; - if (udev && udev->hub) { + if (udev != NULL) { + USB_BUS_UNLOCK(bus); + uhub_explore_handle_re_enumerate(udev); + USB_BUS_LOCK(bus); + } + + if (udev != NULL && udev->hub != NULL) { if (bus->do_probe) { bus->do_probe = 0; |
