Index: share/man/man9/device_set_rebiddable.9
===================================================================
--- share/man/man9/device_set_rebiddable.9
+++ share/man/man9/device_set_rebiddable.9
@@ -0,0 +1,78 @@
+.\" -*- nroff -*-
+.\"
+.\" Copyright (c) 2014 Ian Lepore <ian@FreeBSD.org>
+.\"
+.\" All rights reserved.
+.\"
+.\" This program is free software.
+.\"
+.\" Redistribution and use in source and binary forms, with or without
+.\" modification, are permitted provided that the following conditions
+.\" are met:
+.\" 1. Redistributions of source code must retain the above copyright
+.\"    notice, this list of conditions and the following disclaimer.
+.\" 2. Redistributions in binary form must reproduce the above copyright
+.\"    notice, this list of conditions and the following disclaimer in the
+.\"    documentation and/or other materials provided with the distribution.
+.\"
+.\" THIS SOFTWARE IS PROVIDED BY THE DEVELOPERS ``AS IS'' AND ANY EXPRESS OR
+.\" IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+.\" OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
+.\" IN NO EVENT SHALL THE DEVELOPERS BE LIABLE FOR ANY DIRECT, INDIRECT,
+.\" INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+.\" NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+.\" DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+.\" THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+.\" (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
+.\" THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+.\"
+.\" $FreeBSD$
+.\"
+.Dd October 15, 2014
+.Dt DEVICE_SET_REBIDDABLE 9
+.Os
+.Sh NAME
+.Nm device_set_rebiddable
+.Nd indicate willingness to be outbid for a device after initially claiming it
+.Sh SYNOPSIS
+.In sys/param.h
+.In sys/bus.h
+.Ft void
+.Fn device_set_rebiddable "device_t dev"
+.Sh DESCRIPTION
+Device probing and attaching happens in a series of passes during
+system initialization, and also when a new driver module is loaded.
+Within a pass, the
+.Xr DEVICE_PROBE 9
+method of each suitable driver for a device is called to bid for 
+control of the device using numeric return codes.
+At the end of a pass, control of the device is given to the winning
+bidder by calling that driver's
+.Xr DEVICE_ATTACH 9
+method.
+Once a driver has been attached to a device, that device is normally
+not ever probed again.
+.Pp
+A driver can indicate its willingness to have a device it claimed
+re-probed on later passes or when new drivers are loaded by calling
+.Fn device_set_rebiddable .
+The
+.Xr DEVICE_PROBE 9
+method of the driver currently attached to the device is called again
+during the re-bidding process along with the probe methods of all
+other suitable drivers.
+If another driver wins the bidding during the re-probe, the 
+.Xr DEVICE_DETACH 9
+method of the current driver is called before attaching the new driver.
+.Pp
+The
+.Xr DEVICE_PROBE 9
+method of a rebiddable driver may be called at any time, including
+while the driver is attached to the device.
+The probing process must be idempotent and must not perturb the
+current state of the device.
+.Sh SEE ALSO
+.Xr device 9
+.Sh AUTHORS
+This manual page was written by
+.An Ian Lepore .
Index: sys/kern/subr_bus.c
===================================================================
--- sys/kern/subr_bus.c
+++ sys/kern/subr_bus.c
@@ -2192,9 +2192,6 @@
 			 * sure that we have the right description.
 			 */
 			DEVICE_PROBE(child);
-#if 0
-			child->flags |= DF_REBID;
-#endif
 		} else
 			child->flags &= ~DF_REBID;
 		child->state = DS_ALIVE;
@@ -2588,6 +2585,15 @@
 }
 
 /**
+ * @brief Set the DF_REBID flag for the device
+ */
+void
+device_set_rebiddable(device_t dev)
+{
+	dev->flags |= DF_REBID;
+}
+
+/**
  * @brief Set the DF_QUIET flag for the device
  */
 void
Index: sys/sys/bus.h
===================================================================
--- sys/sys/bus.h
+++ sys/sys/bus.h
@@ -466,6 +466,7 @@
 int	device_set_devclass(device_t dev, const char *classname);
 int	device_set_driver(device_t dev, driver_t *driver);
 void	device_set_flags(device_t dev, u_int32_t flags);
+void	device_set_rebiddable(device_t dev);
 void	device_set_softc(device_t dev, void *softc);
 void	device_free_softc(void *softc);
 void	device_claim_softc(device_t dev);