rt2x00: Data and desc pointer initialization

rt2500usb and rt73usb data and desc pointer initialization
was incorrect because it was using uninitialized variables
to determine the length.

In addition rt2500usb used skb_pull and removed the ieee80211
from each received frame instead of using skb_trim to remove
the device descriptor from the frame.

Finally this also fixes the descriptor override when 4 byte
aligning occured. We still need a completely valid descriptor
when using the TX/RX dumping capabilities in debugfs.

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

1 files changed, 15 insertions, 10 deletions

diff --git a/drivers/net/wireless/rt2x00/rt2x00usb.c b/drivers/net/wireless/rt2x00/rt2x00usb.c
index d7d3a271b1b0..a52939aa38af 100644
--- a/drivers/net/wireless/rt2x00/rt2x00usb.c
+++ b/drivers/net/wireless/rt2x00/rt2x00usb.c
@@ -257,6 +257,13 @@ static void rt2x00usb_interrupt_rxdone(struct urb *urb)
         if (urb->actual_length < entry->ring->desc_size || urb->status)
                 goto skip_entry;
 
+        /*
+         * Fill in skb descriptor
+         */
+        skbdesc = get_skb_desc(entry->skb);
+        skbdesc->ring = ring;
+        skbdesc->entry = entry;
+
         memset(&desc, 0, sizeof(desc));
         rt2x00dev->ops->lib->fill_rxdone(entry, &desc);
 
@@ -283,9 +290,6 @@ static void rt2x00usb_interrupt_rxdone(struct urb *urb)
         /*
          * The data behind the ieee80211 header must be
          * aligned on a 4 byte boundary.
-         * After that trim the entire buffer down to only
-         * contain the valid frame data excluding the device
-         * descriptor.
          */
         hdr = (struct ieee80211_hdr *)entry->skb->data;
         header_size =
@@ -295,16 +299,17 @@ static void rt2x00usb_interrupt_rxdone(struct urb *urb)
                 skb_push(entry->skb, 2);
                 memmove(entry->skb->data, entry->skb->data + 2, skb->len - 2);
         }
-        skb_trim(entry->skb, desc.size);
 
         /*
-         * Fill in skb descriptor
+         * Trim the entire buffer down to only contain the valid frame data
+         * excluding the device descriptor. The position of the descriptor
+         * varies. This means that we should check where the descriptor is
+         * and decide if we need to pull the data pointer to exclude the
+         * device descriptor.
          */
-        skbdesc = get_skb_desc(entry->skb);
-        skbdesc->desc_len = entry->ring->desc_size;
-        skbdesc->data_len = entry->skb->len;
-        skbdesc->ring = ring;
-        skbdesc->entry = entry;
+        if (skbdesc->data > skbdesc->desc)
+                skb_pull(entry->skb, skbdesc->desc_len);
+        skb_trim(entry->skb, desc.size);
 
         /*
          * Send the frame to rt2x00lib for further processing.