rt2x00: rt2800: use correct txop value in tx descriptor

rt2800 devices use a different enumeration to specify what IFS values should
be used on frame transmission compared to the other rt2x00 devices. Hence,
create a new enum called txop that contains the valid values.

Furthermore use the appropriate txop values as found in the ralink drivers:
- TXOP_BACKOFF for management frames
- TXOP_SIFS for subsequent fragments in a burst
- TXOP_HTTXOP for all data frames

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

5 files changed, 31 insertions, 2 deletions

diff --git a/drivers/net/wireless/rt2x00/rt2800pci.c b/drivers/net/wireless/rt2x00/rt2800pci.c
index f08b6a37bf2d..df2c3fb8b4b6 100644
--- a/drivers/net/wireless/rt2x00/rt2800pci.c
+++ b/drivers/net/wireless/rt2x00/rt2800pci.c
@@ -643,7 +643,7 @@ static int rt2800pci_write_tx_data(struct queue_entry* entry,
         rt2x00_set_field32(&word, TXWI_W0_AMPDU,
                            test_bit(ENTRY_TXD_HT_AMPDU, &txdesc->flags));
         rt2x00_set_field32(&word, TXWI_W0_MPDU_DENSITY, txdesc->mpdu_density);
-        rt2x00_set_field32(&word, TXWI_W0_TX_OP, txdesc->ifs);
+        rt2x00_set_field32(&word, TXWI_W0_TX_OP, txdesc->txop);
         rt2x00_set_field32(&word, TXWI_W0_MCS, txdesc->mcs);
         rt2x00_set_field32(&word, TXWI_W0_BW,
                            test_bit(ENTRY_TXD_HT_BW_40, &txdesc->flags));
diff --git a/drivers/net/wireless/rt2x00/rt2800usb.c b/drivers/net/wireless/rt2x00/rt2800usb.c
index 67f8234f24d0..94b68127811e 100644
--- a/drivers/net/wireless/rt2x00/rt2800usb.c
+++ b/drivers/net/wireless/rt2x00/rt2800usb.c
@@ -417,7 +417,7 @@ static void rt2800usb_write_tx_desc(struct rt2x00_dev *rt2x00dev,
         rt2x00_set_field32(&word, TXWI_W0_AMPDU,
                            test_bit(ENTRY_TXD_HT_AMPDU, &txdesc->flags));
         rt2x00_set_field32(&word, TXWI_W0_MPDU_DENSITY, txdesc->mpdu_density);
-        rt2x00_set_field32(&word, TXWI_W0_TX_OP, txdesc->ifs);
+        rt2x00_set_field32(&word, TXWI_W0_TX_OP, txdesc->txop);
         rt2x00_set_field32(&word, TXWI_W0_MCS, txdesc->mcs);
         rt2x00_set_field32(&word, TXWI_W0_BW,
                            test_bit(ENTRY_TXD_HT_BW_40, &txdesc->flags));
diff --git a/drivers/net/wireless/rt2x00/rt2x00ht.c b/drivers/net/wireless/rt2x00/rt2x00ht.c
index 1056c92143a8..5a407602ce3e 100644
--- a/drivers/net/wireless/rt2x00/rt2x00ht.c
+++ b/drivers/net/wireless/rt2x00/rt2x00ht.c
@@ -35,6 +35,7 @@ void rt2x00ht_create_tx_descriptor(struct queue_entry *entry,
 {
         struct ieee80211_tx_info *tx_info = IEEE80211_SKB_CB(entry->skb);
         struct ieee80211_tx_rate *txrate = &tx_info->control.rates[0];
+        struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)entry->skb->data;
 
         if (tx_info->control.sta)
                 txdesc->mpdu_density =
@@ -66,4 +67,20 @@ void rt2x00ht_create_tx_descriptor(struct queue_entry *entry,
                 __set_bit(ENTRY_TXD_HT_BW_40, &txdesc->flags);
         if (txrate->flags & IEEE80211_TX_RC_SHORT_GI)
                 __set_bit(ENTRY_TXD_HT_SHORT_GI, &txdesc->flags);
+
+        /*
+         * Determine IFS values
+         * - Use TXOP_BACKOFF for management frames
+         * - Use TXOP_SIFS for fragment bursts
+         * - Use TXOP_HTTXOP for everything else
+         *
+         * Note: rt2800 devices won't use CTS protection (if used)
+         * for frames not transmitted with TXOP_HTTXOP
+         */
+        if (ieee80211_is_mgmt(hdr->frame_control))
+                txdesc->txop = TXOP_BACKOFF;
+        else if (!(tx_info->flags & IEEE80211_TX_CTL_FIRST_FRAGMENT))
+                txdesc->txop = TXOP_SIFS;
+        else
+                txdesc->txop = TXOP_HTTXOP;
 }
diff --git a/drivers/net/wireless/rt2x00/rt2x00queue.h b/drivers/net/wireless/rt2x00/rt2x00queue.h
index 94a48c174d67..36a957adc1f9 100644
--- a/drivers/net/wireless/rt2x00/rt2x00queue.h
+++ b/drivers/net/wireless/rt2x00/rt2x00queue.h
@@ -299,6 +299,7 @@ enum txentry_desc_flags {
  * @retry_limit: Max number of retries.
  * @aifs: AIFS value.
  * @ifs: IFS value.
+ * @txop: IFS value for 11n capable chips.
  * @cw_min: cwmin value.
  * @cw_max: cwmax value.
  * @cipher: Cipher type used for encryption.
@@ -328,6 +329,7 @@ struct txentry_desc {
         short retry_limit;
         short aifs;
         short ifs;
+        short txop;
         short cw_min;
         short cw_max;
 
diff --git a/drivers/net/wireless/rt2x00/rt2x00reg.h b/drivers/net/wireless/rt2x00/rt2x00reg.h
index 603bfc0adaa3..b9fe94873ee0 100644
--- a/drivers/net/wireless/rt2x00/rt2x00reg.h
+++ b/drivers/net/wireless/rt2x00/rt2x00reg.h
@@ -101,6 +101,16 @@ enum ifs {
 };
 
 /*
+ * IFS backoff values for HT devices
+ */
+enum txop {
+        TXOP_HTTXOP = 0,
+        TXOP_PIFS = 1,
+        TXOP_SIFS = 2,
+        TXOP_BACKOFF = 3,
+};
+
+/*
  * Cipher types for hardware encryption
  */
 enum cipher {