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rt2x00: Fix rt2800 USB TX Path DMA issue

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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@ralinktech.com>
Signed-off-by: Ivo van Doorn <IvDoorn@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
This commit is contained in:
RA-Jay Hung 2010-11-13 19:11:46 +01:00 committed by John W. Linville
parent ef8397cfb3
commit b43d63bd69
1 changed files with 26 additions and 13 deletions
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39
drivers/net/wireless/rt2x00/rt2800usb.c
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@ -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;
}
static void rt2800usb_write_tx_data(struct queue_entry *entry,
struct txentry_desc *txdesc)
{
u8 padding_len;
/*
* 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 ------------->|
*/
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);
}
/*
* TX data initialization
*/
static int rt2800usb_get_tx_data_len(struct queue_entry *entry)
{
int length;
/*
* 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.
*/
length = roundup(entry->skb->len + 4, 4);
length += (4 * !(length % entry->queue->usb_maxpacket));
return length;
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,