From: RA-Jay Hung <Jay_Hung@xxxxxxxxxxxxxx>
rt2800usb chips need to add 1~3 bytes zero padding after each 802.11 header & payload,
and at the end need to add 4 bytes zero padding whether doing TX bulk aggregation or not,
TXINFO_W0_USB_DMA_TX_PKT_LEN in TXINFO must include 1-3 bytes padding after 802.11 header & payload
but do not include 4 bytes end zero padding.
In rt2800usb_get_tx_data_len do not consider multiple of the USB packet size case, sometimes this will
cause USB DMA problem.
Signed-off-by: RA-Jay Hung <jay_hung@xxxxxxxxxxxxxx>
Signed-off-by: Ivo van Doorn <IvDoorn@xxxxxxxxx>
---
drivers/net/wireless/rt2x00/rt2800usb.c | 39 ++++++++++++++++++++----------
1 files changed, 26 insertions(+), 13 deletions(-)
diff --git a/drivers/net/wireless/rt2x00/rt2800usb.c b/drivers/net/wireless/rt2x00/rt2800usb.c
index 2933bf1..935b76d 100644
--- a/drivers/net/wireless/rt2x00/rt2800usb.c
+++ b/drivers/net/wireless/rt2x00/rt2800usb.c
@@ -307,8 +307,14 @@ static void rt2800usb_write_tx_desc(struct queue_entry *entry,
* Initialize TXINFO descriptor
*/
rt2x00_desc_read(txi, 0, &word);
+
+ /*
+ * The size of TXINFO_W0_USB_DMA_TX_PKT_LEN is
+ * TXWI + 802.11 header + L2 pad + payload + pad,
+ * so need to decrease size of TXINFO and USB end pad.
+ */
rt2x00_set_field32(&word, TXINFO_W0_USB_DMA_TX_PKT_LEN,
- entry->skb->len - TXINFO_DESC_SIZE);
+ entry->skb->len - TXINFO_DESC_SIZE - 4);
rt2x00_set_field32(&word, TXINFO_W0_WIV,
!test_bit(ENTRY_TXD_ENCRYPT_IV, &txdesc->flags));
rt2x00_set_field32(&word, TXINFO_W0_QSEL, 2);
@@ -326,22 +332,29 @@ static void rt2800usb_write_tx_desc(struct queue_entry *entry,
skbdesc->desc_len = TXINFO_DESC_SIZE + TXWI_DESC_SIZE;
}
-/*
- * TX data initialization
- */
-static int rt2800usb_get_tx_data_len(struct queue_entry *entry)
+static void rt2800usb_write_tx_data(struct queue_entry *entry,
+ struct txentry_desc *txdesc)
{
- int length;
+ u8 padding_len;
/*
- * The length _must_ include 4 bytes padding,
- * it should always be multiple of 4,
- * but it must _not_ be a multiple of the USB packet size.
+ * pad(1~3 bytes) is added after each 802.11 payload.
+ * USB end pad(4 bytes) is added at each USB bulk out packet end.
+ * TX frame format is :
+ * | TXINFO | TXWI | 802.11 header | L2 pad | payload | pad | USB end pad |
+ * |<------------- tx_pkt_len ------------->|
*/
- length = roundup(entry->skb->len + 4, 4);
- length += (4 * !(length % entry->queue->usb_maxpacket));
+ rt2800_write_tx_data(entry, txdesc);
+ padding_len = roundup(entry->skb->len + 4, 4) - entry->skb->len;
+ memset(skb_put(entry->skb, padding_len), 0, padding_len);
+}
- return length;
+/*
+ * TX data initialization
+ */
+static int rt2800usb_get_tx_data_len(struct queue_entry *entry)
+{
+ return entry->skb->len;
}
/*
@@ -579,7 +592,7 @@ static const struct rt2x00lib_ops rt2800usb_rt2x00_ops = {
.link_tuner = rt2800_link_tuner,
.watchdog = rt2800usb_watchdog,
.write_tx_desc = rt2800usb_write_tx_desc,
- .write_tx_data = rt2800_write_tx_data,
+ .write_tx_data = rt2800usb_write_tx_data,
.write_beacon = rt2800_write_beacon,
.get_tx_data_len = rt2800usb_get_tx_data_len,
.kick_tx_queue = rt2x00usb_kick_tx_queue,
--
1.7.2.3
--
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