netdev - [net-next-2.6 4/7] igbvf: remove Tx hang detection

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Message-Id: <1298545109-8990-5-git-send-email-jeffrey.t.kirsher@intel.com>
Date:	Thu, 24 Feb 2011 02:58:26 -0800
From:	Jeff Kirsher <jeffrey.t.kirsher@...el.com>
To:	davem@...emloft.net
Cc:	Lior Levy <lior.levy@...el.com>, netdev@...r.kernel.org,
	gospo@...hat.com, bphilips@...ell.com,
	Jeff Kirsher <jeffrey.t.kirsher@...el.com>
Subject: [net-next-2.6 4/7] igbvf: remove Tx hang detection

From: Lior Levy <lior.levy@...el.com>

Removed Tx hang detection mechanism from igbvf.
This mechanism has no affect and can cause false alarm message in some cases.

Signed-off-by: Lior Levy <lior.levy@...el.com>
Tested-by: Jeff Pieper <jeffrey.e.pieper@...el.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@...el.com>
---
 drivers/net/igbvf/igbvf.h  |    3 --
 drivers/net/igbvf/netdev.c |   60 --------------------------------------------
 2 files changed, 0 insertions(+), 63 deletions(-)

diff --git a/drivers/net/igbvf/igbvf.h b/drivers/net/igbvf/igbvf.h
index 990c329..d5dad5d 100644
--- a/drivers/net/igbvf/igbvf.h
+++ b/drivers/net/igbvf/igbvf.h
@@ -201,9 +201,6 @@ struct igbvf_adapter {
 	unsigned int restart_queue;
 	u32 txd_cmd;
 
-	bool detect_tx_hung;
-	u8 tx_timeout_factor;
-
 	u32 tx_int_delay;
 	u32 tx_abs_int_delay;
 
diff --git a/drivers/net/igbvf/netdev.c b/drivers/net/igbvf/netdev.c
index 6352c81..42fdf59 100644
--- a/drivers/net/igbvf/netdev.c
+++ b/drivers/net/igbvf/netdev.c
@@ -396,35 +396,6 @@ static void igbvf_put_txbuf(struct igbvf_adapter *adapter,
 	buffer_info->time_stamp = 0;
 }
 
-static void igbvf_print_tx_hang(struct igbvf_adapter *adapter)
-{
-	struct igbvf_ring *tx_ring = adapter->tx_ring;
-	unsigned int i = tx_ring->next_to_clean;
-	unsigned int eop = tx_ring->buffer_info[i].next_to_watch;
-	union e1000_adv_tx_desc *eop_desc = IGBVF_TX_DESC_ADV(*tx_ring, eop);
-
-	/* detected Tx unit hang */
-	dev_err(&adapter->pdev->dev,
-	        "Detected Tx Unit Hang:\n"
-	        "  TDH                  <%x>\n"
-	        "  TDT                  <%x>\n"
-	        "  next_to_use          <%x>\n"
-	        "  next_to_clean        <%x>\n"
-	        "buffer_info[next_to_clean]:\n"
-	        "  time_stamp           <%lx>\n"
-	        "  next_to_watch        <%x>\n"
-	        "  jiffies              <%lx>\n"
-	        "  next_to_watch.status <%x>\n",
-	        readl(adapter->hw.hw_addr + tx_ring->head),
-	        readl(adapter->hw.hw_addr + tx_ring->tail),
-	        tx_ring->next_to_use,
-	        tx_ring->next_to_clean,
-	        tx_ring->buffer_info[eop].time_stamp,
-	        eop,
-	        jiffies,
-	        eop_desc->wb.status);
-}
-
 /**
  * igbvf_setup_tx_resources - allocate Tx resources (Descriptors)
  * @adapter: board private structure
@@ -771,7 +742,6 @@ static void igbvf_set_itr(struct igbvf_adapter *adapter)
 static bool igbvf_clean_tx_irq(struct igbvf_ring *tx_ring)
 {
 	struct igbvf_adapter *adapter = tx_ring->adapter;
-	struct e1000_hw *hw = &adapter->hw;
 	struct net_device *netdev = adapter->netdev;
 	struct igbvf_buffer *buffer_info;
 	struct sk_buff *skb;
@@ -832,22 +802,6 @@ static bool igbvf_clean_tx_irq(struct igbvf_ring *tx_ring)
 		}
 	}
 
-	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].time_stamp &&
-		    time_after(jiffies, tx_ring->buffer_info[i].time_stamp +
-		               (adapter->tx_timeout_factor * HZ)) &&
-		    !(er32(STATUS) & E1000_STATUS_TXOFF)) {
-
-			tx_desc = IGBVF_TX_DESC_ADV(*tx_ring, i);
-			/* detected Tx unit hang */
-			igbvf_print_tx_hang(adapter);
-
-			netif_stop_queue(netdev);
-		}
-	}
 	adapter->net_stats.tx_bytes += total_bytes;
 	adapter->net_stats.tx_packets += total_packets;
 	return count < tx_ring->count;
@@ -1863,17 +1817,6 @@ static void igbvf_watchdog_task(struct work_struct *work)
 			                          &adapter->link_duplex);
 			igbvf_print_link_info(adapter);
 
-			/* adjust timeout factor according to speed/duplex */
-			adapter->tx_timeout_factor = 1;
-			switch (adapter->link_speed) {
-			case SPEED_10:
-				adapter->tx_timeout_factor = 16;
-				break;
-			case SPEED_100:
-				/* maybe add some timeout factor ? */
-				break;
-			}
-
 			netif_carrier_on(netdev);
 			netif_wake_queue(netdev);
 		}
@@ -1907,9 +1850,6 @@ static void igbvf_watchdog_task(struct work_struct *work)
 	/* Cause software interrupt to ensure Rx ring is cleaned */
 	ew32(EICS, adapter->rx_ring->eims_value);
 
-	/* Force detection of hung controller every watchdog period */
-	adapter->detect_tx_hung = 1;
-
 	/* Reset the timer */
 	if (!test_bit(__IGBVF_DOWN, &adapter->state))
 		mod_timer(&adapter->watchdog_timer,
-- 
1.7.4

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