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Commit 745b1ae3 authored by Helmut Schaa's avatar Helmut Schaa Committed by John W. Linville
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rt2x00: rt2800pci: fix tx path by not accessing the skb after it was DMA mapped 



rt2800pci used the callback write_tx_desc to write the tx descriptor but
also to update the txwi which is part of the dma mapped skb. Since the
memory was already DMA mapped _before_ the call to write_tx_desc the
device didn't get the txwi data at all or only sporadically.

The call order is basically as follows (from rt2x00queue.c):
1) write_tx_data
2) rt2x00queue_map_txskb
3) write_tx_desc

Hence, we shouldn't touch the skb in write_tx_desc anymore.

To fix this issue create a new rt2800pci_write_tx_data callback and use it
for updating the txwi _before_ the memory gets DMA mapped.

The tx descriptor is still written (as before) in write_tx_desc.

This patch allows basic TX on an rt305x soc device but I'm pretty sure
that it will fix pci based cards as well. I can associate just fine with
an AP now but I wasn't able to get a wpa secured connection working yet.

Signed-off-by: default avatarHelmut Schaa <helmut.schaa@googlemail.com>
Acked-by: default avatarGertjan van Wingerde <gwingerde@gmail.com>
Signed-off-by: default avatarJohn W. Linville <linville@tuxdriver.com>
parent 41086693

drivers/net/wireless/rt2x00/rt2800pci.c

+27 −7
Original line number Diff line number Diff line
@@ -613,15 +613,23 @@ static int rt2800pci_set_device_state(struct rt2x00_dev *rt2x00dev, 
/*

 * TX descriptor initialization

 */

static void rt2800pci_write_tx_desc(struct rt2x00_dev *rt2x00dev,

				    struct sk_buff *skb,

static int rt2800pci_write_tx_data(struct queue_entry* entry,

				   struct txentry_desc *txdesc)

{

	struct skb_frame_desc *skbdesc = get_skb_frame_desc(skb);

	__le32 *txd = skbdesc->desc;

	__le32 *txwi = (__le32 *)(skb->data - rt2x00dev->ops->extra_tx_headroom);

	struct rt2x00_dev *rt2x00dev = entry->queue->rt2x00dev;

	struct sk_buff *skb = entry->skb;

	struct skb_frame_desc *skbdesc;

	int ret;

	__le32 *txwi;

	u32 word;



	ret = rt2x00pci_write_tx_data(entry, txdesc);

	if (ret)

		return ret;



	skbdesc = get_skb_frame_desc(skb);

	txwi = (__le32 *)(skb->data - rt2x00dev->ops->extra_tx_headroom);



	/*

	 * Initialize TX Info descriptor

	 */
@@ -670,6 +678,18 @@ static void rt2800pci_write_tx_desc(struct rt2x00_dev *rt2x00dev, 
	_rt2x00_desc_write(txwi, 2, 0 /* skbdesc->iv[0] */);

	_rt2x00_desc_write(txwi, 3, 0 /* skbdesc->iv[1] */);



	return 0;

}





static void rt2800pci_write_tx_desc(struct rt2x00_dev *rt2x00dev,

				    struct sk_buff *skb,

				    struct txentry_desc *txdesc)

{

	struct skb_frame_desc *skbdesc = get_skb_frame_desc(skb);

	__le32 *txd = skbdesc->desc;

	u32 word;



	/*

	 * The buffers pointed by SD_PTR0/SD_LEN0 and SD_PTR1/SD_LEN1

	 * must contains a TXWI structure + 802.11 header + padding + 802.11
@@ -1135,7 +1155,7 @@ static const struct rt2x00lib_ops rt2800pci_rt2x00_ops = { 
	.reset_tuner		= rt2800_reset_tuner,

	.link_tuner		= rt2800_link_tuner,

	.write_tx_desc		= rt2800pci_write_tx_desc,

	.write_tx_data		= rt2x00pci_write_tx_data,

	.write_tx_data		= rt2800pci_write_tx_data,

	.write_beacon		= rt2800pci_write_beacon,

	.kick_tx_queue		= rt2800pci_kick_tx_queue,

	.kill_tx_queue		= rt2800pci_kill_tx_queue,