redonkable/alistair23-linux
redonkable/alistair23-linux
1
0
Fork 0
Code Releases Activity

rt2x00: rt2800pci: fix tx path by not accessing the skb after it was DMA mapped

Browse source 
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: Helmut Schaa <helmut.schaa@googlemail.com>
Acked-by: Gertjan van Wingerde <gwingerde@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
This commit is contained in:
Helmut Schaa 2010-04-15 09:13:35 +02:00 committed by John W. Linville
parent 410866930e
commit 745b1ae31b
1 changed files with 27 additions and 7 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

34
drivers/net/wireless/rt2x00/rt2800pci.c
View file

@ -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,
struct txentry_desc *txdesc)
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,