wifi: iwlwifi: mvm: Add locking to the rate read flow

The rs_drv_get_rate flow reads the lq_sta to return the optimal rate
for tx frames. This read flow is not protected thereby leaving
a small window, a few instructions wide, open to contention by an
asynchronous rate update. Indeed this race condition was hit and the
update occurred in the middle of the read.

Fix this by locking the lq_sta struct during read.

Signed-off-by: Ariel Malamud <ariel.malamud@intel.com>
Change-Id: I15290b78e0d966c1b68278263776ca9de841d5fe
Signed-off-by: Gregory Greenman <gregory.greenman@intel.com>
1 file changed