[2/4] wl1271: Fix TX starvation

Commit Message

Ido Yariv Oct. 11, 2010, 8:48 a.m. UTC

None

Patch

diff --git a/drivers/net/wireless/wl12xx/wl1271_main.c b/drivers/net/wireless/wl12xx/wl1271_main.c
index 48a4b99..5643834 100644
--- a/drivers/net/wireless/wl12xx/wl1271_main.c
+++ b/drivers/net/wireless/wl12xx/wl1271_main.c
@@ -458,7 +458,6 @@  static void wl1271_fw_status(struct wl1271 *wl,
 			     struct wl1271_fw_status *status)
 {
 	struct timespec ts;
-	u32 total = 0;
 	int i;
 
 	wl1271_raw_read(wl, FW_STATUS_ADDR, status, sizeof(*status), false);
@@ -478,13 +477,8 @@  static void wl1271_fw_status(struct wl1271 *wl,
 		wl->tx_blocks_freed[i] =
 			le32_to_cpu(status->tx_released_blks[i]);
 		wl->tx_blocks_available += cnt;
-		total += cnt;
 	}
 
-	/* if more blocks are available now, schedule some tx work */
-	if (total && !skb_queue_empty(&wl->tx_queue))
-		ieee80211_queue_work(wl->hw, &wl->tx_work);
-
 	/* update the host-chipset time offset */
 	getnstimeofday(&ts);
 	wl->time_offset = (timespec_to_ns(&ts) >> 10) -
@@ -499,6 +493,7 @@  static void wl1271_irq_work(struct work_struct *work)
 	u32 intr;
 	int loopcount = WL1271_IRQ_MAX_LOOPS;
 	unsigned long flags;
+	u32 prev_tx_blocks;
 	struct wl1271 *wl =
 		container_of(work, struct wl1271, irq_work);
 
@@ -519,6 +514,7 @@  static void wl1271_irq_work(struct work_struct *work)
 		spin_unlock_irqrestore(&wl->wl_lock, flags);
 		loopcount--;
 
+		prev_tx_blocks = wl->tx_blocks_available;
 		wl1271_fw_status(wl, wl->fw_status);
 		intr = le32_to_cpu(wl->fw_status->intr);
 		if (!intr) {
@@ -537,6 +533,17 @@  static void wl1271_irq_work(struct work_struct *work)
 			    (wl->tx_results_count & 0xff))
 				wl1271_tx_complete(wl);
 
+			/* Check if any tx blocks were freed */
+			if ((wl->tx_blocks_available > prev_tx_blocks) &&
+					!skb_queue_empty(&wl->tx_queue)) {
+				/*
+				 * In order to avoid starvation of the TX path,
+				 * call the work function directly.
+				 */
+				cancel_work_sync(&wl->tx_work);
+				wl1271_tx_work_locked(wl);
+			}
+
 			wl1271_rx(wl, wl->fw_status);
 		}
 
diff --git a/drivers/net/wireless/wl12xx/wl1271_tx.c b/drivers/net/wireless/wl12xx/wl1271_tx.c
index 63bc52c..90a8909 100644
--- a/drivers/net/wireless/wl12xx/wl1271_tx.c
+++ b/drivers/net/wireless/wl12xx/wl1271_tx.c
@@ -204,9 +204,8 @@  u32 wl1271_tx_enabled_rates_get(struct wl1271 *wl, u32 rate_set)
 	return enabled_rates;
 }
 
-void wl1271_tx_work(struct work_struct *work)
+void wl1271_tx_work_locked(struct wl1271 *wl)
 {
-	struct wl1271 *wl = container_of(work, struct wl1271, tx_work);
 	struct sk_buff *skb;
 	bool woken_up = false;
 	u32 sta_rates = 0;
@@ -223,8 +222,6 @@  void wl1271_tx_work(struct work_struct *work)
 		spin_unlock_irqrestore(&wl->wl_lock, flags);
 	}
 
-	mutex_lock(&wl->mutex);
-
 	if (unlikely(wl->state == WL1271_STATE_OFF))
 		goto out;
 
@@ -286,7 +283,14 @@  out_ack:
 out:
 	if (woken_up)
 		wl1271_ps_elp_sleep(wl);
+}
 
+void wl1271_tx_work(struct work_struct *work)
+{
+	struct wl1271 *wl = container_of(work, struct wl1271, tx_work);
+
+	mutex_lock(&wl->mutex);
+	wl1271_tx_work_locked(wl);
 	mutex_unlock(&wl->mutex);
 }
 
diff --git a/drivers/net/wireless/wl12xx/wl1271_tx.h b/drivers/net/wireless/wl12xx/wl1271_tx.h
index d12a129..f1c9065 100644
--- a/drivers/net/wireless/wl12xx/wl1271_tx.h
+++ b/drivers/net/wireless/wl12xx/wl1271_tx.h
@@ -140,6 +140,7 @@  static inline int wl1271_tx_get_queue(int queue)
 }
 
 void wl1271_tx_work(struct work_struct *work);
+void wl1271_tx_work_locked(struct wl1271 *wl);
 void wl1271_tx_complete(struct wl1271 *wl);
 void wl1271_tx_reset(struct wl1271 *wl);
 void wl1271_tx_flush(struct wl1271 *wl);