rt2x00: Don't overwrite beacon buffers in pairwise key setup

rt2800 devices use parts of the pariwise key table to store the beacon
frames for beacon 6 and 7. To not overwrite the beacon frame buffers
limit the number of entries we store in the pairwise key table to 222.

Also add some descriptive comments about this shared memory usage.

Signed-off-by: Helmut Schaa <helmut.schaa@googlemail.com>
Signed-off-by: Ivo van Doorn <IvDoorn@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

1 files changed, 5 insertions, 1 deletions

diff --git a/drivers/net/wireless/rt2x00/rt2800lib.c b/drivers/net/wireless/rt2x00/rt2800lib.c
index c7076deaece..daa32ae4286 100644
--- a/drivers/net/wireless/rt2x00/rt2800lib.c
+++ b/drivers/net/wireless/rt2x00/rt2800lib.c
@@ -1031,8 +1031,12 @@ int rt2800_config_pairwise_key(struct rt2x00_dev *rt2x00dev,
                  * 1 pairwise key is possible per AID, this means that the AID
                  * equals our hw_key_idx. Make sure the WCID starts _after_ the
                  * last possible shared key entry.
+                 *
+                 * Since parts of the pairwise key table might be shared with
+                 * the beacon frame buffers 6 & 7 we should only write into the
+                 * first 222 entries.
                  */
-                if (crypto->aid > (256 - 32))
+                if (crypto->aid > (222 - 32))
                         return -ENOSPC;
 
                 key->hw_key_idx = 32 + crypto->aid;