tree 05f3f6410bc376e7a28f0d9fcca686993e65591a
parent 2a00def4d6e50cbfa7588887fdbe2a97042e42bb
author Larry Finger <Larry.Finger@lwfinger.net> 1342035448 -0500
committer John W. Linville <linville@tuxdriver.com> 1342121238 -0400

rtlwifi: rtl8192cu: Change buffer allocation for synchronous reads

In commit a7959c1, the USB part of rtlwifi was switched to convert
_usb_read_sync() to using a preallocated buffer rather than one
that has been acquired using kmalloc. Although this routine is named
as though it were synchronous, there seem to be simultaneous users,
and the selection of the index to the data buffer is not multi-user
safe. This situation is addressed by adding a new spinlock. The routine
cannot sleep, thus a mutex is not allowed.

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