mac80211: fix max HT rate processing on mac80211
The max MCS index is 76, fix the higher check to allow through
frames received at MCS 76. This is a non-issue for current drivers
as MCS 76 is only possible with a device supporting 4 spatial
streams.
While at it change the WARN_ON() on invalid HT rates to a WARN()
to provide more useful information. This will help debug issues
when the driver is passing up a bogus HT rate value.
The rate must map to a valid MCS index which can be any of the
values in the set [0 - 76] (inclusive).
Signed-off-by: Luis R. Rodriguez <lrodriguez@atheros.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/net/mac80211/rx.c b/net/mac80211/rx.c
index 7647836..006cf89 100644
--- a/net/mac80211/rx.c
+++ b/net/mac80211/rx.c
@@ -2441,9 +2441,21 @@
goto drop;
if (status->flag & RX_FLAG_HT) {
- /* rate_idx is MCS index */
- if (WARN_ON(status->rate_idx < 0 ||
- status->rate_idx >= 76))
+ /*
+ * rate_idx is MCS index, which can be [0-76] as documented on:
+ *
+ * http://wireless.kernel.org/en/developers/Documentation/ieee80211/802.11n
+ *
+ * Anything else would be some sort of driver or hardware error.
+ * The driver should catch hardware errors.
+ */
+ if (WARN((status->rate_idx < 0 ||
+ status->rate_idx > 76),
+ "Rate marked as an HT rate but passed "
+ "status->rate_idx is not "
+ "an MCS index [0-76]: %d (0x%02x)\n",
+ status->rate_idx,
+ status->rate_idx))
goto drop;
/* HT rates are not in the table - use the highest legacy rate
* for now since other parts of mac80211 may not yet be fully