redonkable/alistair23-linux
redonkable/alistair23-linux
1
0
Fork 0
Code Releases Activity

rt2x00: Fix lockdep warning in rt2x00lib_probe_dev()

Browse source 
The rt2x00dev->intf_work workqueue is never initialized when a driver is
probed for a non-existent device (in this case rt2500usb). On such a
path we call rt2x00lib_remove_dev() to free any resources initialized
during the probe before we use INIT_WORK to initialize the workqueue.
This causes lockdep to get confused since the lock used in the workqueue
hasn't been initialized yet but is now being acquired during
cancel_work_sync() called by rt2x00lib_remove_dev().

Fix this by initializing the workqueue first before we attempt to probe
the device. This should make lockdep happy and avoid breaking any
assumptions about how the library cleans up after a probe fails.

phy0 -> rt2x00lib_probe_dev: Error - Failed to allocate device.
INFO: trying to register non-static key.
the code is fine but needs lockdep annotation.
turning off the locking correctness validator.
Pid: 2027, comm: modprobe Not tainted 2.6.35-rc5+ #60
Call Trace:
 [<ffffffff8105fe59>] register_lock_class+0x152/0x31f
 [<ffffffff81344a00>] ? usb_control_msg+0xd5/0x111
 [<ffffffff81061bde>] __lock_acquire+0xce/0xcf4
 [<ffffffff8105f6fd>] ? trace_hardirqs_off+0xd/0xf
 [<ffffffff81492aef>] ?  _raw_spin_unlock_irqrestore+0x33/0x41
 [<ffffffff810628d5>] lock_acquire+0xd1/0xf7
 [<ffffffff8104f037>] ? __cancel_work_timer+0x99/0x17e
 [<ffffffff8104f06e>] __cancel_work_timer+0xd0/0x17e
 [<ffffffff8104f037>] ? __cancel_work_timer+0x99/0x17e
 [<ffffffff8104f136>] cancel_work_sync+0xb/0xd
 [<ffffffffa0096675>] rt2x00lib_remove_dev+0x25/0xb0 [rt2x00lib]
 [<ffffffffa0096bf7>] rt2x00lib_probe_dev+0x380/0x3ed [rt2x00lib]
 [<ffffffff811d78a7>] ? __raw_spin_lock_init+0x31/0x52
 [<ffffffffa00bbd2c>] ? T.676+0xe/0x10 [rt2x00usb]
 [<ffffffffa00bbe4f>] rt2x00usb_probe+0x121/0x15e [rt2x00usb]
 [<ffffffff813468bd>] usb_probe_interface+0x151/0x19e
 [<ffffffff812ea08e>] driver_probe_device+0xa7/0x136
 [<ffffffff812ea167>] __driver_attach+0x4a/0x66
 [<ffffffff812ea11d>] ? __driver_attach+0x0/0x66
 [<ffffffff812e96ca>] bus_for_each_dev+0x54/0x89
 [<ffffffff812e9efd>] driver_attach+0x19/0x1b
 [<ffffffff812e9b64>] bus_add_driver+0xb4/0x204
 [<ffffffff812ea41b>] driver_register+0x98/0x109
 [<ffffffff813465dd>] usb_register_driver+0xb2/0x173
 [<ffffffffa00ca000>] ? rt2500usb_init+0x0/0x20 [rt2500usb]
 [<ffffffffa00ca01e>] rt2500usb_init+0x1e/0x20 [rt2500usb]
 [<ffffffff81000203>] do_one_initcall+0x6d/0x17a
 [<ffffffff8106cae8>] sys_init_module+0x9c/0x1e0
 [<ffffffff8100296b>] system_call_fastpath+0x16/0x1b

Signed-off-by: Stephen Boyd <bebarino@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
This commit is contained in:
Stephen Boyd 2010-07-16 09:50:10 -07:00 committed by John W. Linville
parent 0f4da2d77e
commit 9acd56d3f2
1 changed files with 5 additions and 5 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

10
drivers/net/wireless/rt2x00/rt2x00dev.c
View file

@ -853,6 +853,11 @@ int rt2x00lib_probe_dev(struct rt2x00_dev *rt2x00dev)
BIT(NL80211_IFTYPE_MESH_POINT) |
BIT(NL80211_IFTYPE_WDS);
/*
* Initialize configuration work.
*/
INIT_WORK(&rt2x00dev->intf_work, rt2x00lib_intf_scheduled);
/*
* Let the driver probe the device to detect the capabilities.
*/
@ -862,11 +867,6 @@ int rt2x00lib_probe_dev(struct rt2x00_dev *rt2x00dev)
goto exit;
}
/*
* Initialize configuration work.
*/
INIT_WORK(&rt2x00dev->intf_work, rt2x00lib_intf_scheduled);
/*
* Allocate queue array.
*/