rtlwifi: Fix oops on unload

rtlwifi: Fix oops on unload

Under some circumstances, a PCI-based driver reports the following OOPs:

Mar 19 08:14:35 kvothe kernel: [ 6584.626011] Oops: 0000 [#1] SMP
--snip--
Mar 19 08:14:35 kvothe kernel: [ 6584.626011] Pid: 19627, comm: rmmod
Not tainted 3.2.9-2.fc16.x86_64 #1 LENOVO 05962RU/05962RU
Mar 19 08:14:35 kvothe kernel: [ 6584.626011] RIP:
0010:[<ffffffffa0418d39>]  [<ffffffffa0418d39>]
rtl92ce_get_desc+0x19/0xd0 [rtl8192ce]
--snip--
Mar 19 08:14:35 kvothe kernel: [ 6584.626011] Process rmmod (pid:
19627, threadinfo ffff880050262000, task ffff8801156d5cc0)
Mar 19 08:14:35 kvothe kernel: [ 6584.626011] Stack:
Mar 19 08:14:35 kvothe kernel: [ 6584.626011]  0000000000000002
ffff8801176c2540 ffff880050263ca8 ffffffffa03348e7
Mar 19 08:14:35 kvothe kernel: [ 6584.626011]  0000000000000282
0000000180150014 ffff880050263fd8 ffff8801176c2810
Mar 19 08:14:35 kvothe kernel: [ 6584.626011]  ffff880050263bc8
ffffffff810550e2 00000000000002c0 ffff8801176c0d40
Mar 19 08:14:35 kvothe kernel: [ 6584.626011] Call Trace:
Mar 19 08:14:35 kvothe kernel: [ 6584.626011]  [<ffffffffa03348e7>]
_rtl_pci_rx_interrupt+0x187/0x650 [rtlwifi]
--snip--
Mar 19 08:14:35 kvothe kernel: [ 6584.626011] Code: ff 09 d0 89 07 48
83 c4 08 5b 5d c3 66 0f 1f 44 00 00 55 48 89 e5 53 48 83 ec 08 66 66
66 66 90 40 84 f6 89 d3 74 13 84 d2 75 57 <8b> 07 48 83 c4 08 5b 5d c1
e8 1f c3 0f 1f 00 84 d2 74 ed 80 fa
Mar 19 08:14:35 kvothe kernel: [ 6584.626011] RIP
[<ffffffffa0418d39>] rtl92ce_get_desc+0x19/0xd0 [rtl8192ce]
Mar 19 08:14:35 kvothe kernel: [ 6584.626011]  RSP <ffff880050263b58>
Mar 19 08:14:35 kvothe kernel: [ 6584.626011] CR2: 00000000000006e0
Mar 19 08:14:35 kvothe kernel: [ 6584.646491] ---[ end trace
8636c766dcfbe0e6 ]---

This oops is due to interrupts not being disabled in this particular path.

Reported-by: Dave Airlie <airlied@gmail.com>
Tested-by: Dave Airlie <airlied@gmail.com>
Signed-off-by: Larry Finger <Larry.Finger@lwfinger.net>
Cc: Stable <stable@vger.kernel.org>
Signed-off-by: John W. Linville <linville@tuxdriver.com>