iwlagn: fix rts cts protection

Currently the driver will try to protect all frames,
which leads to a lot of odd things like sending an
RTS with a zeroed RA before multicast frames, which
is clearly bogus.

In order to fix all of this, we need to take a step
back and see what we need to achieve:
 * we need RTS/CTS protection if requested by
   the AP for the BSS, mac80211 tells us this
 * in that case, CTS-to-self should only be
   enabled when mac80211 tells us
 * additionally, as a hardware workaround, on
   some devices we have to protect aggregated
   frames with RTS

To achieve the first two items, set up the RXON
accordingly and set the protection required flag
in the transmit command when mac80211 requests
protection for the frame.

To achieve the last item, set the rate-control
RTS-requested flag for all stations that we have
aggregation sessions with, and set the protection
required flag when sending aggregated frames (on
those devices where this is required).

Since otherwise bugs can occur, do not allow the
user to override the RTS-for-aggregation setting
from sysfs any more.

Finally, also clean up the way all these flags get
set in the driver and move everything into the
device-specific functions.

Cc: stable@kernel.org [2.6.35]
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Wey-Yi Guy <wey-yi.w.guy@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

1 files changed, 21 insertions, 64 deletions

diff --git a/drivers/net/wireless/iwlwifi/iwl-agn.c b/drivers/net/wireless/iwlwifi/iwl-agn.c
index 35337b1e7cac..c1882fd8345d 100644
--- a/drivers/net/wireless/iwlwifi/iwl-agn.c
+++ b/drivers/net/wireless/iwlwifi/iwl-agn.c
@@ -202,13 +202,6 @@ int iwl_commit_rxon(struct iwl_priv *priv)
 
 	priv->start_calib = 0;
 	if (new_assoc) {
-		/*
-		 * allow CTS-to-self if possible for new association.
-		 * this is relevant only for 5000 series and up,
-		 * but will not damage 4965
-		 */
-		priv->staging_rxon.flags |= RXON_FLG_SELF_CTS_EN;
-
 		/* Apply the new configuration
 		 * RXON assoc doesn't clear the station table in uCode,
 		 */
@@ -1618,45 +1611,9 @@ static ssize_t store_tx_power(struct device *d,
 
 static DEVICE_ATTR(tx_power, S_IWUSR | S_IRUGO, show_tx_power, store_tx_power);
 
-static ssize_t show_rts_ht_protection(struct device *d,
-			     struct device_attribute *attr, char *buf)
-{
-	struct iwl_priv *priv = dev_get_drvdata(d);
-
-	return sprintf(buf, "%s\n",
-		priv->cfg->use_rts_for_ht ? "RTS/CTS" : "CTS-to-self");
-}
-
-static ssize_t store_rts_ht_protection(struct device *d,
-			      struct device_attribute *attr,
-			      const char *buf, size_t count)
-{
-	struct iwl_priv *priv = dev_get_drvdata(d);
-	unsigned long val;
-	int ret;
-
-	ret = strict_strtoul(buf, 10, &val);
-	if (ret)
-		IWL_INFO(priv, "Input is not in decimal form.\n");
-	else {
-		if (!iwl_is_associated(priv))
-			priv->cfg->use_rts_for_ht = val ? true : false;
-		else
-			IWL_ERR(priv, "Sta associated with AP - "
-				"Change protection mechanism is not allowed\n");
-		ret = count;
-	}
-	return ret;
-}
-
-static DEVICE_ATTR(rts_ht_protection, S_IWUSR | S_IRUGO,
-			show_rts_ht_protection, store_rts_ht_protection);
-
-
 static struct attribute *iwl_sysfs_entries[] = {
 	&dev_attr_temperature.attr,
 	&dev_attr_tx_power.attr,
-	&dev_attr_rts_ht_protection.attr,
 #ifdef CONFIG_IWLWIFI_DEBUG
 	&dev_attr_debug_level.attr,
 #endif
@@ -3464,25 +3421,6 @@ static int iwl_mac_set_key(struct ieee80211_hw *hw, enum set_key_cmd cmd,
 	return ret;
 }
 
-/*
- * switch to RTS/CTS for TX
- */
-static void iwl_enable_rts_cts(struct iwl_priv *priv)
-{
-
-	if (test_bit(STATUS_EXIT_PENDING, &priv->status))
-		return;
-
-	priv->staging_rxon.flags &= ~RXON_FLG_SELF_CTS_EN;
-	if (!test_bit(STATUS_SCANNING, &priv->status)) {
-		IWL_DEBUG_INFO(priv, "use RTS/CTS protection\n");
-		iwlcore_commit_rxon(priv);
-	} else {
-		/* scanning, defer the request until scan completed */
-		IWL_DEBUG_INFO(priv, "defer setting RTS/CTS protection\n");
-	}
-}
-
 static int iwl_mac_ampdu_action(struct ieee80211_hw *hw,
 				struct ieee80211_vif *vif,
 				enum ieee80211_ampdu_mlme_action action,
@@ -3529,14 +3467,33 @@ static int iwl_mac_ampdu_action(struct ieee80211_hw *hw,
 		}
 		if (test_bit(STATUS_EXIT_PENDING, &priv->status))
 			ret = 0;
+		if (priv->cfg->use_rts_for_aggregation) {
+			struct iwl_station_priv *sta_priv =
+				(void *) sta->drv_priv;
+			/*
+			 * switch off RTS/CTS if it was previously enabled
+			 */
+
+			sta_priv->lq_sta.lq.general_params.flags &=
+				~LINK_QUAL_FLAGS_SET_STA_TLC_RTS_MSK;
+			iwl_send_lq_cmd(priv, &sta_priv->lq_sta.lq,
+				CMD_ASYNC, false);
+		}
 		break;
 	case IEEE80211_AMPDU_TX_OPERATIONAL:
-		if (priv->cfg->use_rts_for_ht) {
+		if (priv->cfg->use_rts_for_aggregation) {
+			struct iwl_station_priv *sta_priv =
+				(void *) sta->drv_priv;
+
 			/*
 			 * switch to RTS/CTS if it is the prefer protection
 			 * method for HT traffic
 			 */
-			iwl_enable_rts_cts(priv);
+
+			sta_priv->lq_sta.lq.general_params.flags |=
+				LINK_QUAL_FLAGS_SET_STA_TLC_RTS_MSK;
+			iwl_send_lq_cmd(priv, &sta_priv->lq_sta.lq,
+				CMD_ASYNC, false);
 		}
 		ret = 0;
 		break;