mac80211: reduce IEEE80211_TX_MAX_RATES

IEEE80211_TX_MAX_RATES can be reduced from 5 to 4 as there
is no current hardware supporting a rate chain with 5 multi
rate stages (mrr), so 4 mrr stages are sufficient.

The memory that is freed within the ieee80211_tx_info struct
will be used in the upcoming Transmission Power Control (TPC)
implementation.

Suggested-by: Felix Fietkau <nbd@openwrt.org>
Signed-off-by: Thomas Huehn <thomas@net.t-labs.tu-berlin.de>
[reword commit message]
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

1 files changed, 1 insertions, 2 deletions

diff --git a/net/mac80211/tx.c b/net/mac80211/tx.c
index 364a1e7b4afa..c9d2175d15c1 100644
--- a/net/mac80211/tx.c
+++ b/net/mac80211/tx.c
@@ -959,8 +959,7 @@ ieee80211_tx_h_fragment(struct ieee80211_tx_data *tx)
                         info->control.rates[1].idx = -1;
                         info->control.rates[2].idx = -1;
                         info->control.rates[3].idx = -1;
-                        info->control.rates[4].idx = -1;
-                        BUILD_BUG_ON(IEEE80211_TX_MAX_RATES != 5);
+                        BUILD_BUG_ON(IEEE80211_TX_MAX_RATES != 4);
                         info->flags &= ~IEEE80211_TX_CTL_RATE_CTRL_PROBE;
                 } else {
                         hdr->frame_control &= ~morefrags;