[PATCH] rt2x00: Add get_tx_data_len callback function

The TX datalen must always be converted to a value rt73 and rt2500usb
understand. Both require to use a different size then skb->len.
First off this is required because the descriptor must be added,
but the second is because the value must be a multiple of either 2 or 4,
and it should not be a multiple of the USB packetmax

Signed-off-by: Ivo van Doorn <IvDoorn@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

4 files changed, 56 insertions, 23 deletions

diff --git a/drivers/net/wireless/rt2x00/rt2500usb.c b/drivers/net/wireless/rt2x00/rt2500usb.c
index c70c677b3f73..f536ff1b5c47 100644
--- a/drivers/net/wireless/rt2x00/rt2500usb.c
+++ b/drivers/net/wireless/rt2x00/rt2500usb.c
@@ -1057,6 +1057,21 @@ static void rt2500usb_write_tx_desc(struct rt2x00_dev *rt2x00dev,
         rt2x00_desc_write(txd, 0, word);
 }
 
+static int rt2500usb_get_tx_data_len(struct rt2x00_dev *rt2x00dev,
+                                     int maxpacket, struct sk_buff *skb)
+{
+        int length;
+
+        /*
+         * The length _must_ be a multiple of 2,
+         * but it must _not_ be a multiple of the USB packet size.
+         */
+        length = roundup(skb->len, 2);
+        length += (2 * !(length % maxpacket));
+
+        return length;
+}
+
 /*
  * TX data initialization
  */
@@ -1653,6 +1668,8 @@ static int rt2500usb_beacon_update(struct ieee80211_hw *hw,
             rt2x00lib_get_ring(rt2x00dev, IEEE80211_TX_QUEUE_BEACON);
         struct data_entry *beacon;
         struct data_entry *guardian;
+        int pipe = usb_sndbulkpipe(usb_dev, 1);
+        int max_packet = usb_maxpacket(usb_dev, pipe, 1);
         int length;
 
         /*
@@ -1679,16 +1696,9 @@ static int rt2500usb_beacon_update(struct ieee80211_hw *hw,
                                                          ring->desc_size),
                                 skb->len - ring->desc_size, control);
 
-        /*
-         * Length passed to usb_fill_urb cannot be an odd number,
-         * so add 1 byte to make it even.
-         */
-        length = skb->len;
-        if (length % 2)
-                length++;
+        length = rt2500usb_get_tx_data_len(rt2x00dev, max_packet, skb);
 
-        usb_fill_bulk_urb(beacon->priv, usb_dev,
-                          usb_sndbulkpipe(usb_dev, 1),
+        usb_fill_bulk_urb(beacon->priv, usb_dev, pipe,
                           skb->data, length, rt2500usb_beacondone, beacon);
 
         beacon->skb = skb;
@@ -1699,8 +1709,7 @@ static int rt2500usb_beacon_update(struct ieee80211_hw *hw,
          * the 'flags' field we are not using for beacons.
          */
         guardian->flags = 0;
-        usb_fill_bulk_urb(guardian->priv, usb_dev,
-                          usb_sndbulkpipe(usb_dev, 1),
+        usb_fill_bulk_urb(guardian->priv, usb_dev, pipe,
                           &guardian->flags, 1, rt2500usb_beacondone, guardian);
 
         /*
@@ -1741,6 +1750,7 @@ static const struct rt2x00lib_ops rt2500usb_rt2x00_ops = {
         .link_tuner             = rt2500usb_link_tuner,
         .write_tx_desc          = rt2500usb_write_tx_desc,
         .write_tx_data          = rt2x00usb_write_tx_data,
+        .get_tx_data_len        = rt2500usb_get_tx_data_len,
         .kick_tx_queue          = rt2500usb_kick_tx_queue,
         .fill_rxdone            = rt2500usb_fill_rxdone,
         .config_mac_addr        = rt2500usb_config_mac_addr,
diff --git a/drivers/net/wireless/rt2x00/rt2x00.h b/drivers/net/wireless/rt2x00/rt2x00.h
index 27bec6ec33df..a392e2a9d087 100644
--- a/drivers/net/wireless/rt2x00/rt2x00.h
+++ b/drivers/net/wireless/rt2x00/rt2x00.h
@@ -396,6 +396,8 @@ struct rt2x00lib_ops {
         int (*write_tx_data) (struct rt2x00_dev *rt2x00dev,
                               struct data_ring *ring, struct sk_buff *skb,
                               struct ieee80211_tx_control *control);
+        int (*get_tx_data_len) (struct rt2x00_dev *rt2x00dev, int maxpacket,
+                                struct sk_buff *skb);
         void (*kick_tx_queue) (struct rt2x00_dev *rt2x00dev,
                                unsigned int queue);
 
diff --git a/drivers/net/wireless/rt2x00/rt2x00usb.c b/drivers/net/wireless/rt2x00/rt2x00usb.c
index 66e47615f2a6..73cc726c4046 100644
--- a/drivers/net/wireless/rt2x00/rt2x00usb.c
+++ b/drivers/net/wireless/rt2x00/rt2x00usb.c
@@ -157,9 +157,10 @@ int rt2x00usb_write_tx_data(struct rt2x00_dev *rt2x00dev,
 {
         struct usb_device *usb_dev =
             interface_to_usbdev(rt2x00dev_usb(rt2x00dev));
-        struct ieee80211_hdr *ieee80211hdr = (struct ieee80211_hdr *)skb->data;
         struct data_entry *entry = rt2x00_get_data_entry(ring);
-        u32 length = skb->len;
+        int pipe = usb_sndbulkpipe(usb_dev, 1);
+        int max_packet = usb_maxpacket(usb_dev, pipe, 1);
+        u32 length;
 
         if (rt2x00_ring_full(ring)) {
                 ieee80211_stop_queue(rt2x00dev->hw, control->queue);
@@ -178,25 +179,29 @@ int rt2x00usb_write_tx_data(struct rt2x00_dev *rt2x00dev,
         /*
          * Add the descriptor in front of the skb.
          */
-        skb_push(skb, rt2x00dev->hw->extra_tx_headroom);
-        memset(skb->data, 0x00, rt2x00dev->hw->extra_tx_headroom);
+        skb_push(skb, ring->desc_size);
+        memset(skb->data, 0, ring->desc_size);
 
         rt2x00lib_write_tx_desc(rt2x00dev, (struct data_desc *)skb->data,
-                                ieee80211hdr, length, control);
+                                (struct ieee80211_hdr *)(skb->data +
+                                                         ring->desc_size),
+                                skb->len - ring->desc_size, control);
         memcpy(&entry->tx_status.control, control, sizeof(*control));
         entry->skb = skb;
 
         /*
-         * Length passed to usb_fill_urb cannot be an odd number,
-         * so add 1 byte to make it even.
+         * USB devices cannot blindly pass the skb->len as the
+         * length of the data to usb_fill_bulk_urb. Pass the skb
+         * to the driver to determine what the length should be.
          */
-        length += rt2x00dev->hw->extra_tx_headroom;
-        if (length % 2)
-                length++;
+        length = rt2x00dev->ops->lib->get_tx_data_len(rt2x00dev,
+                                                      max_packet, skb);
 
+        /*
+         * Initialize URB and send the frame to the device.
+         */
         __set_bit(ENTRY_OWNER_NIC, &entry->flags);
-        usb_fill_bulk_urb(entry->priv, usb_dev,
-                          usb_sndbulkpipe(usb_dev, 1),
+        usb_fill_bulk_urb(entry->priv, usb_dev, pipe,
                           skb->data, length, rt2x00usb_interrupt_txdone, entry);
         usb_submit_urb(entry->priv, GFP_ATOMIC);
 
diff --git a/drivers/net/wireless/rt2x00/rt73usb.c b/drivers/net/wireless/rt2x00/rt73usb.c
index 919cca593bc1..4a78ca79c94a 100644
--- a/drivers/net/wireless/rt2x00/rt73usb.c
+++ b/drivers/net/wireless/rt2x00/rt73usb.c
@@ -1286,6 +1286,21 @@ static void rt73usb_write_tx_desc(struct rt2x00_dev *rt2x00dev,
         rt2x00_desc_write(txd, 0, word);
 }
 
+static int rt73usb_get_tx_data_len(struct rt2x00_dev *rt2x00dev,
+                                   int maxpacket, struct sk_buff *skb)
+{
+        int length;
+
+        /*
+         * The length _must_ be a multiple of 4,
+         * but it must _not_ be a multiple of the USB packet size.
+         */
+        length = roundup(skb->len, 4);
+        length += (4 * !(length % maxpacket));
+
+        return length;
+}
+
 /*
  * TX data initialization
  */
@@ -2012,6 +2027,7 @@ static const struct rt2x00lib_ops rt73usb_rt2x00_ops = {
         .link_tuner             = rt73usb_link_tuner,
         .write_tx_desc          = rt73usb_write_tx_desc,
         .write_tx_data          = rt2x00usb_write_tx_data,
+        .get_tx_data_len        = rt73usb_get_tx_data_len,
         .kick_tx_queue          = rt73usb_kick_tx_queue,
         .fill_rxdone            = rt73usb_fill_rxdone,
         .config_mac_addr        = rt73usb_config_mac_addr,