[003/107] rt2x00: do not drop usb dev reference counter on suspend

From: Greg KH
Date: Wed Nov 02 2011 - 21:33:40 EST


2.6.32-longterm review patch. If anyone has any objections, please let us know.

------------------

From: Stanislaw Gruszka <sgruszka@xxxxxxxxxx>

commit 543cc38c8fe86deba4169977c61eb88491036837 upstream.

When hibernating ->resume may not be called by usb core, but disconnect
and probe instead, so we do not increase the counter after decreasing
it in ->supend. As a result we free memory early, and get crash when
unplugging usb dongle.

BUG: unable to handle kernel paging request at 6b6b6b9f
IP: [<c06909b0>] driver_sysfs_remove+0x10/0x30
*pdpt = 0000000034f21001 *pde = 0000000000000000
Pid: 20, comm: khubd Not tainted 3.1.0-rc1-wl+ #20 LENOVO 6369CTO/6369CTO
EIP: 0060:[<c06909b0>] EFLAGS: 00010202 CPU: 1
EIP is at driver_sysfs_remove+0x10/0x30
EAX: 6b6b6b6b EBX: f52bba34 ECX: 00000000 EDX: 6b6b6b6b
ESI: 6b6b6b6b EDI: c0a0ea20 EBP: f61c9e68 ESP: f61c9e64
DS: 007b ES: 007b FS: 00d8 GS: 00e0 SS: 0068
Process khubd (pid: 20, ti=f61c8000 task=f6138270 task.ti=f61c8000)
Call Trace:
[<c06909ef>] __device_release_driver+0x1f/0xa0
[<c0690b20>] device_release_driver+0x20/0x40
[<c068fd64>] bus_remove_device+0x84/0xe0
[<c068e12a>] ? device_remove_attrs+0x2a/0x80
[<c068e267>] device_del+0xe7/0x170
[<c06d93d4>] usb_disconnect+0xd4/0x180
[<c06d9d61>] hub_thread+0x691/0x1600
[<c0473260>] ? wake_up_bit+0x30/0x30
[<c0442a39>] ? complete+0x49/0x60
[<c06d96d0>] ? hub_disconnect+0xd0/0xd0
[<c06d96d0>] ? hub_disconnect+0xd0/0xd0
[<c0472eb4>] kthread+0x74/0x80
[<c0472e40>] ? kthread_worker_fn+0x150/0x150
[<c0809b3e>] kernel_thread_helper+0x6/0x10

Signed-off-by: Stanislaw Gruszka <sgruszka@xxxxxxxxxx>
Acked-by: Ivo van Doorn <IvDoorn@xxxxxxxxx>
Signed-off-by: John W. Linville <linville@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxx>

---
drivers/net/wireless/rt2x00/rt2x00usb.c | 14 +-------------
1 file changed, 1 insertion(+), 13 deletions(-)

--- a/drivers/net/wireless/rt2x00/rt2x00usb.c
+++ b/drivers/net/wireless/rt2x00/rt2x00usb.c
@@ -703,18 +703,8 @@ int rt2x00usb_suspend(struct usb_interfa
{
struct ieee80211_hw *hw = usb_get_intfdata(usb_intf);
struct rt2x00_dev *rt2x00dev = hw->priv;
- int retval;

- retval = rt2x00lib_suspend(rt2x00dev, state);
- if (retval)
- return retval;
-
- /*
- * Decrease usbdev refcount.
- */
- usb_put_dev(interface_to_usbdev(usb_intf));
-
- return 0;
+ return rt2x00lib_suspend(rt2x00dev, state);
}
EXPORT_SYMBOL_GPL(rt2x00usb_suspend);

@@ -723,8 +713,6 @@ int rt2x00usb_resume(struct usb_interfac
struct ieee80211_hw *hw = usb_get_intfdata(usb_intf);
struct rt2x00_dev *rt2x00dev = hw->priv;

- usb_get_dev(interface_to_usbdev(usb_intf));
-
return rt2x00lib_resume(rt2x00dev);
}
EXPORT_SYMBOL_GPL(rt2x00usb_resume);


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