diff options
Diffstat (limited to 'sys/dev/usb/usb_dev.c')
| -rw-r--r-- | sys/dev/usb/usb_dev.c | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/sys/dev/usb/usb_dev.c b/sys/dev/usb/usb_dev.c index cba8919..b7c6553 100644 --- a/sys/dev/usb/usb_dev.c +++ b/sys/dev/usb/usb_dev.c @@ -1040,9 +1040,14 @@ usb_ioctl(struct cdev *dev, u_long cmd, caddr_t addr, int fflag, struct thread* * Performance optimisation: We try to check for IOCTL's that * don't need the USB reference first. Then we grab the USB * reference if we need it! + * Note that some ioctl_post handlers would need to run with the + * newbus lock held. It cannot be acquired later because it can + * introduce a LOR, so acquire it here. */ + newbus_xlock(); err = usb_ref_device(cpd, &refs, 0 /* no uref */ ); if (err) { + newbus_xunlock(); return (ENXIO); } fflags = cpd->fflags; @@ -1076,6 +1081,7 @@ usb_ioctl(struct cdev *dev, u_long cmd, caddr_t addr, int fflag, struct thread* } done: usb_unref_device(cpd, &refs); + newbus_xunlock(); return (err); } |
