[PATCH net-drivers-2.6 3/10] e1000: Avoid race between e1000_watchdog and e1000_clean_tx_irq
From: Malli Chilakala <hidden>
Date: 2005-02-15 21:25:48
3 Avoid race condition between e1000_watchdog and e1000_clean_tx_irq Signed-off-by: Mallikarjuna R Chilakala <redacted> Signed-off-by: Ganesh Venkatesan <redacted> Signed-off-by: John Ronciak <redacted> diff -up net-drivers-2.6/drivers/net/e1000/e1000.h net-drivers-2.6/drivers/net/e1000.new/e1000.h
--- net-drivers-2.6/drivers/net/e1000/e1000.h 2005-02-01 23:10:24.986106336 -0800
+++ net-drivers-2.6/drivers/net/e1000.new/e1000.h 2005-02-01 23:10:26.474880008 -0800@@ -222,6 +222,7 @@ struct e1000_adapter { uint32_t tx_fifo_size; atomic_t tx_fifo_stall; boolean_t pcix_82544; + boolean_t detect_tx_hung; /* RX */ struct e1000_desc_ring rx_ring;
diff -up net-drivers-2.6/drivers/net/e1000/e1000_main.c net-drivers-2.6/drivers/net/e1000.new/e1000_main.c
--- net-drivers-2.6/drivers/net/e1000/e1000_main.c 2005-02-01 23:10:24.989105880 -0800
+++ net-drivers-2.6/drivers/net/e1000.new/e1000_main.c 2005-02-01 23:10:26.709844288 -0800@@ -1432,7 +1432,6 @@ e1000_watchdog(unsigned long data) struct e1000_adapter *adapter = (struct e1000_adapter *) data; struct net_device *netdev = adapter->netdev; struct e1000_desc_ring *txdr = &adapter->tx_ring; - unsigned int i; uint32_t link; e1000_check_for_link(&adapter->hw);
@@ -1512,12 +1511,8 @@ e1000_watchdog(unsigned long data) /* Cause software interrupt to ensure rx ring is cleaned */ E1000_WRITE_REG(&adapter->hw, ICS, E1000_ICS_RXDMT0); - /* Early detection of hung controller */ - i = txdr->next_to_clean; - if(txdr->buffer_info[i].dma && - time_after(jiffies, txdr->buffer_info[i].time_stamp + HZ) && - !(E1000_READ_REG(&adapter->hw, STATUS) & E1000_STATUS_TXOFF)) - netif_stop_queue(netdev); + /* Force detection of hung controller every watchdog period*/ + adapter->detect_tx_hung = TRUE; /* Reset the timer */ mod_timer(&adapter->watchdog_timer, jiffies + 2 * HZ);
@@ -2245,6 +2240,16 @@ e1000_clean_tx_irq(struct e1000_adapter netif_wake_queue(netdev); spin_unlock(&adapter->tx_lock); + + if(adapter->detect_tx_hung) { + /* detect a transmit hang in hardware, this serializes the + * check with the clearing of time_stamp and movement of i */ + adapter->detect_tx_hung = FALSE; + if(tx_ring->buffer_info[i].dma && + time_after(jiffies, tx_ring->buffer_info[i].time_stamp + HZ) && + !(E1000_READ_REG(&adapter->hw, STATUS) & E1000_STATUS_TXOFF)) + netif_stop_queue(netdev); + } return cleaned; }