[057/272] ath9k_htc: Handle pending URBs properly

Greg KH
2011-02-16T00:19:40Z

From: Sujith Manoharan <Sujith.Manoharan@atheros.com>

commit ff8f59b5bbdf1527235b8c88d859c7d23691324f upstream.

When doing a channel change, the pending URBs have to be killed
properly on calling htc_stop().

This fixes the probe response timeout seen when sending UDP traffic at
a high rate and running background scan at the same time.

Signed-off-by: Sujith Manoharan <Sujith.Manoharan@atheros.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

---
drivers/net/wireless/ath/ath9k/hif_usb.c | 40 +++++++++++++++++++++++++++----
drivers/net/wireless/ath/ath9k/hif_usb.h | 1
2 files changed, 37 insertions(+), 4 deletions(-)

--- a/drivers/net/wireless/ath/ath9k/hif_usb.c
+++ b/drivers/net/wireless/ath/ath9k/hif_usb.c
@@ -144,16 +144,36 @@ static void hif_usb_tx_cb(struct urb *ur
case -ENODEV:
case -ESHUTDOWN:
/*
- * The URB has been killed, free the SKBs
- * and return.
+ * The URB has been killed, free the SKBs.
*/
ath9k_skb_queue_purge(hif_dev, &tx_buf->skb_queue);
- return;
+
+ /*
+ * If the URBs are being flushed, no need to add this
+ * URB to the free list.
+ */
+ spin_lock(&hif_dev->tx.tx_lock);
+ if (hif_dev->tx.flags & HIF_USB_TX_FLUSH) {
+ spin_unlock(&hif_dev->tx.tx_lock);
+ return;
+ }
+ spin_unlock(&hif_dev->tx.tx_lock);
+
+ /*
+ * In the stop() case, this URB has to be added to
+ * the free list.
+ */
+ goto add_free;
default:
break;
}

- /* Check if TX has been stopped */
+ /*
+ * Check if TX has been stopped, this is needed because
+ * this CB could have been invoked just after the TX lock
+ * was released in hif_stop() and kill_urb() hasn't been
+ * called yet.
+ */
spin_lock(&hif_dev->tx.tx_lock);
if (hif_dev->tx.flags & HIF_USB_TX_STOP) {
spin_unlock(&hif_dev->tx.tx_lock);
@@ -305,6 +325,7 @@ static void hif_usb_start(void *hif_hand
static void hif_usb_stop(void *hif_handle, u8 pipe_id)
{
struct hif_device_usb *hif_dev = (struct hif_device_usb *)hif_handle;
+ struct tx_buf *tx_buf = NULL, *tx_buf_tmp = NULL;
unsigned long flags;

spin_lock_irqsave(&hif_dev->tx.tx_lock, flags);
@@ -312,6 +333,12 @@ static void hif_usb_stop(void *hif_handl
hif_dev->tx.tx_skb_cnt = 0;
hif_dev->tx.flags |= HIF_USB_TX_STOP;
spin_unlock_irqrestore(&hif_dev->tx.tx_lock, flags);
+
+ /* The pending URBs have to be canceled. */
+ list_for_each_entry_safe(tx_buf, tx_buf_tmp,
+ &hif_dev->tx.tx_pending, list) {
+ usb_kill_urb(tx_buf->urb);
+ }
}

static int hif_usb_send(void *hif_handle, u8 pipe_id, struct sk_buff *skb,
@@ -578,6 +605,7 @@ free:
static void ath9k_hif_usb_dealloc_tx_urbs(struct hif_device_usb *hif_dev)
{
struct tx_buf *tx_buf = NULL, *tx_buf_tmp = NULL;
+ unsigned long flags;

list_for_each_entry_safe(tx_buf, tx_buf_tmp,
&hif_dev->tx.tx_buf, list) {
@@ -588,6 +616,10 @@ static void ath9k_hif_usb_dealloc_tx_urb
kfree(tx_buf);
}

+ spin_lock_irqsave(&hif_dev->tx.tx_lock, flags);
+ hif_dev->tx.flags |= HIF_USB_TX_FLUSH;
+ spin_unlock_irqrestore(&hif_dev->tx.tx_lock, flags);
+
list_for_each_entry_safe(tx_buf, tx_buf_tmp,
&hif_dev->tx.tx_pending, list) {
usb_kill_urb(tx_buf->urb);
--- a/drivers/net/wireless/ath/ath9k/hif_usb.h
+++ b/drivers/net/wireless/ath/ath9k/hif_usb.h
@@ -62,6 +62,7 @@ struct tx_buf {
};

#define HIF_USB_TX_STOP BIT(0)
+#define HIF_USB_TX_FLUSH BIT(1)

struct hif_usb_tx {
u8 flags;