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authorDavid Fries <david@fries.net>2008-10-16 09:04:38 +0400
committerLinus Torvalds <torvalds@linux-foundation.org>2008-10-16 22:21:49 +0400
commitc30c9b15187e977ab5928f7276e9dfcd8d6f9460 (patch)
treed36d7513c5acf1d39f581625ffa5c1915ae5627f /drivers/w1/w1_family.c
parentdd78c9439fc1e031835bccb934d27b978c72c536 (diff)
downloadlinux-c30c9b15187e977ab5928f7276e9dfcd8d6f9460.tar.xz
W1: fix deadlocks and remove w1_control_thread
w1_control_thread was removed which would wake up every second and process newly registered family codes and complete some final cleanup for a removed master. Those routines were moved to the threads that were previously requesting those operations. A new function w1_reconnect_slaves takes care of reconnecting existing slave devices when a new family code is registered or removed. The removal case was missing and would cause a deadlock waiting for the family code reference count to decrease, which will now happen. A problem with registering a family code was fixed. A slave device would be unattached if it wasn't yet claimed, then attached at the end of the list, two unclaimed slaves would cause an infinite loop. The struct w1_bus_master.search now takes a pointer to the struct w1_master device to avoid searching for it, which would have caused a lock ordering deadlock with the removal of w1_control_thread. Signed-off-by: David Fries <david@fries.net> Signed-off-by: Evgeniy Polyakov <johnpol@2ka.mipt.ru> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'drivers/w1/w1_family.c')
-rw-r--r--drivers/w1/w1_family.c6
1 files changed, 5 insertions, 1 deletions
diff --git a/drivers/w1/w1_family.c b/drivers/w1/w1_family.c
index a3c95bd6890a..8c35f9ccb689 100644
--- a/drivers/w1/w1_family.c
+++ b/drivers/w1/w1_family.c
@@ -53,7 +53,8 @@ int w1_register_family(struct w1_family *newf)
}
spin_unlock(&w1_flock);
- w1_reconnect_slaves(newf);
+ /* check default devices against the new set of drivers */
+ w1_reconnect_slaves(newf, 1);
return ret;
}
@@ -77,6 +78,9 @@ void w1_unregister_family(struct w1_family *fent)
spin_unlock(&w1_flock);
+ /* deatch devices using this family code */
+ w1_reconnect_slaves(fent, 0);
+
while (atomic_read(&fent->refcnt)) {
printk(KERN_INFO "Waiting for family %u to become free: refcnt=%d.\n",
fent->fid, atomic_read(&fent->refcnt));