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rt2x00: Fix txdone race condition

PATCH In review Ivo van Doorn 1 participant 1 message Dec 3, 2006

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Networking Network drivers Networking drivers (wireless)
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Ivo van Doorn

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PATCH 21/26 rt2x00: Fix txdone race condition

Always call ieee80211_wake_queue if the ring is not full after the txrun. The ieee80211_wake_queue is responsible for chacking if the queue was stopped or not.
The current implementation of checking the ring_full before the txdone run was flawed and race conditions could occur that blocked all tx handling.

Signed-off-by Ivo van Doorn <[email protected]>

---

drivers/net/wireless/d80211/rt2x00/rt2400pci.c +1 -7
diff -rU3 wireless-dev-led/drivers/net/wireless/d80211/rt2x00/rt2400pci.c wireless-dev-ringfull/drivers/net/wireless/d80211/rt2x00/rt2400pci.c
@@ -1613,14 +1613,8 @@
 	u32 word;
 	int tx_status;
 	int ack;
-	int ring_full;
 	int rts;
 
-	/*
-	 * Store the current status of the ring.
-	 */
-	ring_full = rt2x00_ring_full(ring);
-
 	while (!rt2x00_ring_empty(ring)) {
 		entry = rt2x00_get_data_entry_done(ring);
 		txd = rt2x00_desc_addr(entry);

@@ -1687,7 +1681,7 @@
 	 * is reenabled when the txdone handler has finished.
 	 */
 	entry = ring->entry;
-	if (ring_full && !rt2x00_ring_full(ring))
+	if (!rt2x00_ring_full(ring))
 		ieee80211_wake_queue(rt2x00dev->hw,
 			entry->tx_status.control.queue);
 }
drivers/net/wireless/d80211/rt2x00/rt2500pci.c +1 -7
diff -rU3 wireless-dev-led/drivers/net/wireless/d80211/rt2x00/rt2500pci.c wireless-dev-ringfull/drivers/net/wireless/d80211/rt2x00/rt2500pci.c
@@ -1776,14 +1776,8 @@
 	u32 word;
 	int tx_status;
 	int ack;
-	int ring_full;
 	int rts;
 
-	/*
-	 * Store the current status of the ring.
-	 */
-	ring_full = rt2x00_ring_full(ring);
-
 	while (!rt2x00_ring_empty(ring)) {
 		entry = rt2x00_get_data_entry_done(ring);
 		txd = rt2x00_desc_addr(entry);

@@ -1850,7 +1844,7 @@
 	 * is reenabled when the txdone handler has finished.
 	 */
 	entry = ring->entry;
-	if (ring_full && !rt2x00_ring_full(ring))
+	if (!rt2x00_ring_full(ring))
 		ieee80211_wake_queue(rt2x00dev->hw,
 			entry->tx_status.control.queue);
 }
drivers/net/wireless/d80211/rt2x00/rt2500usb.c +1 -7
diff -rU3 wireless-dev-led/drivers/net/wireless/d80211/rt2x00/rt2500usb.c wireless-dev-ringfull/drivers/net/wireless/d80211/rt2x00/rt2500usb.c
@@ -1753,14 +1753,8 @@
 	struct urb *urb;
 	u32 word;
 	int ack;
-	int ring_full;
 	int rts;
 
-	/*
-	 * Store the current status of the ring.
-	 */
-	ring_full = rt2x00_ring_full(ring);
-
 	 while (!rt2x00_ring_empty(ring)) {
 		entry = rt2x00_get_data_entry_done(ring);
 		txd = rt2x00_txdesc_addr(entry);

@@ -1821,7 +1815,7 @@
 	 * is reenabled when the txdone handler has finished.
 	 */
 	entry = ring->entry;
-	if (ring_full && !rt2x00_ring_full(ring))
+	if (!rt2x00_ring_full(ring))
 		ieee80211_wake_queue(rt2x00dev->hw,
 			entry->tx_status.control.queue);
 }
drivers/net/wireless/d80211/rt2x00/rt61pci.c +2 -7
diff -rU3 wireless-dev-led/drivers/net/wireless/d80211/rt2x00/rt61pci.c wireless-dev-ringfull/drivers/net/wireless/d80211/rt2x00/rt61pci.c
@@ -2235,7 +2235,6 @@
 	u32 word;
 	int tx_status;
 	int ack;
-	int ring_full;
 	int rts;
 
 	txd = rt2x00_desc_addr(entry);

@@ -2285,11 +2284,6 @@
 	CLEAR_FLAG(entry, ENTRY_RTS_FRAME);
 	entry->skb = NULL;
 
-	/*
-	 * Store the current status of the ring.
-	 */
-	ring_full = rt2x00_ring_full(entry->ring);
-
 	rt2x00_ring_index_done_inc(entry->ring);
 
 	/*

@@ -2297,7 +2291,8 @@
 	 * we must make sure the packet queue in the d80211 stack
 	 * is reenabled when the txdone handler has finished.
 	 */
-	if (ring_full && !rt2x00_ring_full(entry->ring))
+	entry = ring->entry;
+	if (!rt2x00_ring_full(ring))
 		ieee80211_wake_queue(rt2x00dev->hw,
 			entry->tx_status.control.queue);
 }
drivers/net/wireless/d80211/rt2x00/rt73usb.c +1 -7
diff -rU3 wireless-dev-led/drivers/net/wireless/d80211/rt2x00/rt73usb.c wireless-dev-ringfull/drivers/net/wireless/d80211/rt2x00/rt73usb.c
@@ -2026,14 +2026,8 @@
 	struct urb *urb;
 	u32 word;
 	int ack;
-	int ring_full;
 	int rts;
 
-	/*
-	 * Store the current status of the ring.
-	 */
-	ring_full = rt2x00_ring_full(ring);
-
 	while (!rt2x00_ring_empty(ring)) {
 		entry = rt2x00_get_data_entry_done(ring);
 		txd = rt2x00_desc_addr(entry);

@@ -2096,7 +2090,7 @@
 	 * is reenabled when the txdone handler has finished.
 	 */
 	entry = ring->entry;
-	if (ring_full && !rt2x00_ring_full(ring))
+	if (!rt2x00_ring_full(ring))
 		ieee80211_wake_queue(rt2x00dev->hw,
 			entry->tx_status.control.queue);
 }