e1000e: incorporate napi_struct changes from net-2.6.24.git

This incorporates the new napi_struct changes into e1000e. Included bugfix for ifdown hang from Krishna Kumar for e1000.

Disabling polling is no longer needed at init time, so remove napi_disable() call from _probe().

Signed-off-by Auke Kok <[email protected]>

---

 drivers/net/e1000e/e1000.h  |    2 ++
 drivers/net/e1000e/netdev.c |   39 ++++++++++++++++-----------------------
 2 files changed, 18 insertions(+), 23 deletions(-)

drivers/net/e1000e/e1000.h +2 -0

index c57e35a..d2499bb 100644
@@ -187,6 +187,8 @@ struct e1000_adapter {
 	struct e1000_ring *tx_ring /* One per active queue */
 						____cacheline_aligned_in_smp;
 
+	struct napi_struct napi;
+
 	unsigned long tx_queue_len;
 	unsigned int restart_queue;
 	u32 txd_cmd;

drivers/net/e1000e/netdev.c +16 -23

index 372da46..f8ec537 100644
@@ -1149,12 +1149,12 @@ static irqreturn_t e1000_intr_msi(int irq, void *data)
 			mod_timer(&adapter->watchdog_timer, jiffies + 1);
 	}
 
-	if (netif_rx_schedule_prep(netdev)) {
+	if (netif_rx_schedule_prep(netdev, &adapter->napi)) {
 		adapter->total_tx_bytes = 0;
 		adapter->total_tx_packets = 0;
 		adapter->total_rx_bytes = 0;
 		adapter->total_rx_packets = 0;
-		__netif_rx_schedule(netdev);
+		__netif_rx_schedule(netdev, &adapter->napi);
 	} else {
 		atomic_dec(&adapter->irq_sem);
 	}

@@ -1212,12 +1212,12 @@ static irqreturn_t e1000_intr(int irq, void *data)
 			mod_timer(&adapter->watchdog_timer, jiffies + 1);
 	}
 
-	if (netif_rx_schedule_prep(netdev)) {
+	if (netif_rx_schedule_prep(netdev, &adapter->napi)) {
 		adapter->total_tx_bytes = 0;
 		adapter->total_tx_packets = 0;
 		adapter->total_rx_bytes = 0;
 		adapter->total_rx_packets = 0;
-		__netif_rx_schedule(netdev);
+		__netif_rx_schedule(netdev, &adapter->napi);
 	} else {
 		atomic_dec(&adapter->irq_sem);
 	}

@@ -1662,10 +1662,10 @@ set_itr_now:
  * e1000_clean - NAPI Rx polling callback
  * @adapter: board private structure
  **/
-static int e1000_clean(struct net_device *poll_dev, int *budget)
+static int e1000_clean(struct napi_struct *napi, int budget)
 {
-	struct e1000_adapter *adapter;
-	int work_to_do = min(*budget, poll_dev->quota);
+	struct e1000_adapter *adapter = container_of(napi, struct e1000_adapter, napi);
+	struct net_device *poll_dev = adapter->netdev;
 	int tx_cleaned = 0, work_done = 0;
 
 	/* Must NOT use netdev_priv macro here. */

@@ -1684,25 +1684,20 @@ static int e1000_clean(struct net_device *poll_dev, int *budget)
 		spin_unlock(&adapter->tx_queue_lock);
 	}
 
-	adapter->clean_rx(adapter, &work_done, work_to_do);
-	*budget -= work_done;
-	poll_dev->quota -= work_done;
+	adapter->clean_rx(adapter, &work_done, budget);
 
 	/* If no Tx and not enough Rx work done, exit the polling mode */
-	if ((!tx_cleaned && (work_done == 0)) ||
+	if ((tx_cleaned && (work_done < budget)) ||
 	   !netif_running(poll_dev)) {
 quit_polling:
 		if (adapter->itr_setting & 3)
 			e1000_set_itr(adapter);
-		netif_rx_complete(poll_dev);
-		if (test_bit(__E1000_DOWN, &adapter->state))
-			atomic_dec(&adapter->irq_sem);
-		else
-			e1000_irq_enable(adapter);
+		netif_rx_complete(poll_dev, napi);
+		e1000_irq_enable(adapter);
 		return 0;
 	}
 
-	return 1;
+	return work_done;
 }
 
 static void e1000_vlan_rx_add_vid(struct net_device *netdev, u16 vid)

@@ -2439,7 +2434,7 @@ int e1000e_up(struct e1000_adapter *adapter)
 
 	clear_bit(__E1000_DOWN, &adapter->state);
 
-	netif_poll_enable(adapter->netdev);
+	napi_enable(&adapter->napi);
 	e1000_irq_enable(adapter);
 
 	/* fire a link change interrupt to start the watchdog */

@@ -2472,7 +2467,7 @@ void e1000e_down(struct e1000_adapter *adapter)
 	e1e_flush();
 	msleep(10);
 
-	netif_poll_disable(netdev);
+	napi_disable(&adapter->napi);
 	e1000_irq_disable(adapter);
 
 	del_timer_sync(&adapter->watchdog_timer);

@@ -2605,7 +2600,7 @@ static int e1000_open(struct net_device *netdev)
 	/* From here on the code is the same as e1000e_up() */
 	clear_bit(__E1000_DOWN, &adapter->state);
 
-	netif_poll_enable(netdev);
+	napi_enable(&adapter->napi);
 
 	e1000_irq_enable(adapter);
 

@@ -4090,8 +4085,7 @@ static int __devinit e1000_probe(struct pci_dev *pdev,
 	e1000e_set_ethtool_ops(netdev);
 	netdev->tx_timeout		= &e1000_tx_timeout;
 	netdev->watchdog_timeo		= 5 * HZ;
-	netdev->poll			= &e1000_clean;
-	netdev->weight			= 64;
+	netif_napi_add(netdev, &adapter->napi, e1000_clean, 64);
 	netdev->vlan_rx_register	= e1000_vlan_rx_register;
 	netdev->vlan_rx_add_vid		= e1000_vlan_rx_add_vid;
 	netdev->vlan_rx_kill_vid	= e1000_vlan_rx_kill_vid;

@@ -4260,7 +4254,6 @@ static int __devinit e1000_probe(struct pci_dev *pdev,
 	/* tell the stack to leave us alone until e1000_open() is called */
 	netif_carrier_off(netdev);
 	netif_stop_queue(netdev);
-	netif_poll_disable(netdev);
 
 	strcpy(netdev->name, "eth%d");
 	err = register_netdev(netdev);

david,

while testing this patch I noticed that the poll routine is now called 100% of the time, and since I'm not doing much different than before, I suspec that something in the new napi code is staying in polling mode forever? Since e1000e is pretty much the same code as e1000, I doubt the problem is there, but you can probably tell better. ideas?

Yes a correct observation. I've spotted this bug too and it caused by the policy change in the NAPI scheduling. Look at tx_cleaned.

I suggest we revert this change for now.

From e8cbb449155000eecc6e855ea71510fecfc7d5ee Mon Sep 17 00:00:00 2001

From: Robert Olsson <[email protected]>
Date: Sat, 8 Sep 2007 09:53:49 +0200

Quoted 4 lines

Yes a correct observation. I've spotted this bug too and it caused by the policy change in the NAPI scheduling. Look at tx_cleaned.

I suggest we revert this change for now.

The tx_cleaned logic change was not intentional, and that's the bug that makes e1000 spin endlessly in NAPI.

The other part, the work_done < budget part, was intentional so I'm going to keep it in there for now. I've checked in the patch below to deal with this.

I suspect the check "work_done == 0" is some shamans dance to get slightly better performance, but it's 1) wrong and
2) at best needs to be explained in a comment and fully quantified.

From e8cbb449155000eecc6e855ea71510fecfc7d5ee Mon Sep 17 00:00:00 2001
From: David S. Miller <davem@kimchee.(none)>
Date: Wed, 12 Sep 2007 16:50:32 +0200
Subject: [PATCH] [E1000]: Fix unintended NAPI breakout logic change.

The inversion of the !tx_cleaned test in e1000_clean() was not intentional, we just wanted to change the "work_done == 0" to "work_done < budget"

Noticed by Robert Olsson.

Signed-off-by David S. Miller <[email protected]>

---
 drivers/net/e1000/e1000_main.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

drivers/net/e1000/e1000_main.c +0 -0

index 7b0bcdb..58bb758 100644

Quoted 8 lines · David Miller

drivers/net/e1000/e1000_main.c +0 -0

index 7b0bcdb..58bb758 100644
@@ -3944,7 +3944,7 @@ e1000_clean(struct napi_struct *napi, int budget)
 	                  &work_done, budget);
 

drivers/net/e1000/e1000_main.c e1000_clean(struct napi_struct *napi, int budget) · line 3950

Quoted 6 lines

drivers/net/e1000/e1000_main.c +1 -1

 	/* If no Tx and not enough Rx work done, exit the polling mode */
-	if ((tx_cleaned && (work_done < budget)) ||
+	if ((!tx_cleaned && (work_done < budget)) ||
 	   !netif_running(poll_dev)) {
 quit_polling:
 		if (likely(adapter->itr_setting & 3))

Ack, this is exactly what I did to fix e1000e as well.