mac80211: add rts-cts for dynamic SMPS stations

Checking whether dynamic SMPS is enabled at the receiver station for which packet is intended to be transmitted. Enable RTS protection for multi-stream rates for such packets.

---
 net/mac80211/tx.c |   20 +++++++++++++++++++-
 1 files changed, 19 insertions(+), 1 deletions(-)

index aad0bf5..38c2ec6 100644
@@ -621,6 +621,7 @@ ieee80211_tx_h_rate_ctrl(struct ieee80211_tx_data *tx)
     int i;
     u32 len;
     bool inval = false, rts = false, short_preamble = false;
+    bool dyn_smps = false;
     struct ieee80211_tx_rate_control txrc;
     bool assoc = false;
 

@@ -738,6 +739,13 @@ ieee80211_tx_h_rate_ctrl(struct ieee80211_tx_data *tx)
         info->control.rts_cts_rate_idx = baserate;
     }
 
+    /* check if dynamic SMPS is on at receiving station */
+    if (tx->sta) {
+        if (tx->sta->sta.smps_mode == WLAN_HT_CAP_SM_PS_DYNAMIC) {
+            dyn_smps = true;
+        }
+    }
+
     for (i = 0; i < IEEE80211_TX_MAX_RATES; i++) {
         /*
          * make sure there's no valid rate following

@@ -766,7 +774,17 @@ ieee80211_tx_h_rate_ctrl(struct ieee80211_tx_data *tx)
         if (rts)
             info->control.rates[i].flags |=
                 IEEE80211_TX_RC_USE_RTS_CTS;
-
+        /*
+         * set up RTS protection for multi-stream rates if dynamic
+         * SMPS is enabled for the receiving station
+         */
+        if (dyn_smps) {
+            if ((info->control.rates[i].idx > 7) &&
+                (info->control.rates[i].idx != 32))
+                info->control.rates[i].flags |=
+                    IEEE80211_TX_RC_USE_RTS_CTS;        
+        }
+        
         /* RC is busted */
         if (WARN_ON_ONCE(info->control.rates[i].idx >=
                  sband->n_bitrates)) {

Vivek,

Please work with some of your colleagues at posedge to submit a proper patch. This is formatted completely wrongly in many ways.

Hi Johannes,

I ran checkpatch.pl script and found some trailing white spaces in the patch which i have now corrected.

Also,i had initially placed my code in minstrel_ht_get_rate but saw that the minstrel code is being changed.
hence, moved the code in to ieee80211_tx_h_rate_ctrl function.

there is a check in this function

        if (info->control.rates[i].flags & IEEE80211_TX_RC_MCS) {
            WARN_ON(info->control.rates[i].idx > 76);
            continue;
        }

I feel it would be okay to move the code for dyn_smps within this loop as this would solve the check for MCS rates.

however i am not sure whether all ht rates flag settings need to be handled within minstrel_ht?

        if (info->control.rates[i].flags & IEEE80211_TX_RC_MCS) {
            WARN_ON(info->control.rates[i].idx > 76);

+ if (dyn_smps) {
+ if ((info->control.rates[i].idx > 7) &&
+ (info->control.rates[i].idx != 32))
+ info->control.rates[i].flags |=
+ IEEE80211_TX_RC_USE_RTS_CTS;

            continue;
        }

awaiting your inputs

thanks and regards
Vivek