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Commit 7cca336a authored by Claudiu Manoil's avatar Claudiu Manoil Committed by David S. Miller
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gianfar: Remove clean_rx_ring race from gfar_ethtool 



gfar_clean_rx_ring() was designed to be called from napi
(rx softirq) context to do the Rx processing. Calling it
from a process context like this is a bug as it will
clearly race with the napi Rx processing.

There's also no point in initializing num_txbdfree since
startup_gfar() already does that, when bringing the device
up again (after reset). Changing num_txbdfree "on-the-fly"
like this is also subject to race conditions.  num_txbdfree
is handled by the Tx processing path and the device reset
procedure.  Also, don't assume that num_rx_queues is always
equal to num_tx_queues.

Signed-off-by: default avatarClaudiu Manoil <claudiu.manoil@freescale.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent c10650b6

drivers/net/ethernet/freescale/gianfar_ethtool.c

+8 −55
Original line number Diff line number Diff line
@@ -44,9 +44,6 @@ 


#include "gianfar.h"



extern int gfar_clean_rx_ring(struct gfar_priv_rx_q *rx_queue,

			      int rx_work_limit);



#define GFAR_MAX_COAL_USECS 0xffff

#define GFAR_MAX_COAL_FRAMES 0xff

static void gfar_fill_stats(struct net_device *dev, struct ethtool_stats *dummy,
@@ -466,15 +463,13 @@ static void gfar_gringparam(struct net_device *dev, 
}



/* Change the current ring parameters, stopping the controller if

 * necessary so that we don't mess things up while we're in

 * motion.  We wait for the ring to be clean before reallocating

 * the rings.

 * necessary so that we don't mess things up while we're in motion.

 */

static int gfar_sringparam(struct net_device *dev,

			   struct ethtool_ringparam *rvals)

{

	struct gfar_private *priv = netdev_priv(dev);

	int err = 0, i = 0;

	int err = 0, i;



	if (rvals->rx_pending > GFAR_RX_MAX_RING_SIZE)

		return -EINVAL;
@@ -492,38 +487,15 @@ static int gfar_sringparam(struct net_device *dev, 
		return -EINVAL;

	}





	if (dev->flags & IFF_UP) {

		unsigned long flags;



		/* Halt TX and RX, and process the frames which

		 * have already been received

		 */

		local_irq_save(flags);

		lock_tx_qs(priv);

		lock_rx_qs(priv);



		gfar_halt(priv);



		unlock_rx_qs(priv);

		unlock_tx_qs(priv);

		local_irq_restore(flags);



		for (i = 0; i < priv->num_rx_queues; i++)

			gfar_clean_rx_ring(priv->rx_queue[i],

					   priv->rx_queue[i]->rx_ring_size);



		/* Now we take down the rings to rebuild them */

	if (dev->flags & IFF_UP)

		stop_gfar(dev);

	}



	/* Change the size */

	for (i = 0; i < priv->num_rx_queues; i++) {

	/* Change the sizes */

	for (i = 0; i < priv->num_rx_queues; i++)

		priv->rx_queue[i]->rx_ring_size = rvals->rx_pending;



	for (i = 0; i < priv->num_tx_queues; i++)

		priv->tx_queue[i]->tx_ring_size = rvals->tx_pending;

		priv->tx_queue[i]->num_txbdfree =

			priv->tx_queue[i]->tx_ring_size;

	}



	/* Rebuild the rings with the new size */

	if (dev->flags & IFF_UP) {
@@ -607,10 +579,8 @@ static int gfar_spauseparam(struct net_device *dev, 


int gfar_set_features(struct net_device *dev, netdev_features_t features)

{

	struct gfar_private *priv = netdev_priv(dev);

	unsigned long flags;

	int err = 0, i = 0;

	netdev_features_t changed = dev->features ^ features;

	int err = 0;



	if (changed & (NETIF_F_HW_VLAN_CTAG_TX|NETIF_F_HW_VLAN_CTAG_RX))

		gfar_vlan_mode(dev, features);
@@ -619,23 +589,6 @@ int gfar_set_features(struct net_device *dev, netdev_features_t features) 
		return 0;



	if (dev->flags & IFF_UP) {

		/* Halt TX and RX, and process the frames which

		 * have already been received

		 */

		local_irq_save(flags);

		lock_tx_qs(priv);

		lock_rx_qs(priv);



		gfar_halt(priv);



		unlock_tx_qs(priv);

		unlock_rx_qs(priv);

		local_irq_restore(flags);



		for (i = 0; i < priv->num_rx_queues; i++)

			gfar_clean_rx_ring(priv->rx_queue[i],

					   priv->rx_queue[i]->rx_ring_size);



		/* Now we take down the rings to rebuild them */

		stop_gfar(dev);