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Commit 94c9e5a8 authored by Jesse Brandeburg's avatar Jesse Brandeburg Committed by David S. Miller
Browse files

e1000: allow ethtool coalesece to adjust interrupts per second 



This patch allows on-the-fly adjustment of the interrupts per second generated
by e1000 devices 82545/82546 (hardware support of ITR register is a
requirement)

adjust using this command:
ethtool -C eth0 rx-usecs 10

where 10 is 10 microseconds per interrupt interval, so 10 = 100,000 interrupts
per second, and 125 = 8000 interrupts per second.

changes should be immediate.

1,3 are special values and indicate the automatic tuning mode to the driver,
where 1 is 4000-90000 interrupts per second and 3 is 4000-20000 interrupts
per second and is the driver default.

Signed-off-by: default avatarJesse Brandeburg <jesse.brandeburg@intel.com>
Signed-off-by: default avatarJeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent f77139c0

drivers/net/e1000/e1000.h

+3 −0
Original line number Diff line number Diff line
@@ -111,6 +111,9 @@ do { \ 
#define E1000_MIN_RXD                       80

#define E1000_MAX_82544_RXD               4096



#define E1000_MIN_ITR_USECS		10 /* 100000 irq/sec */

#define E1000_MAX_ITR_USECS		10000 /* 100    irq/sec */



/* this is the size past which hardware will drop packets when setting LPE=0 */

#define MAXIMUM_ETHERNET_VLAN_SIZE 1522

drivers/net/e1000/e1000_ethtool.c

+50 −1
Original line number Diff line number Diff line
@@ -1904,6 +1904,53 @@ static int e1000_phys_id(struct net_device *netdev, u32 data) 
	return 0;

}



static int e1000_get_coalesce(struct net_device *netdev,

			      struct ethtool_coalesce *ec)

{

	struct e1000_adapter *adapter = netdev_priv(netdev);



	if (adapter->hw.mac_type < e1000_82545)

		return -EOPNOTSUPP;



	if (adapter->itr_setting <= 3)

		ec->rx_coalesce_usecs = adapter->itr_setting;

	else

		ec->rx_coalesce_usecs = 1000000 / adapter->itr_setting;



	return 0;

}



static int e1000_set_coalesce(struct net_device *netdev,

			      struct ethtool_coalesce *ec)

{

	struct e1000_adapter *adapter = netdev_priv(netdev);

	struct e1000_hw *hw = &adapter->hw;



	if (hw->mac_type < e1000_82545)

		return -EOPNOTSUPP;



	if ((ec->rx_coalesce_usecs > E1000_MAX_ITR_USECS) ||

	    ((ec->rx_coalesce_usecs > 3) &&

	     (ec->rx_coalesce_usecs < E1000_MIN_ITR_USECS)) ||

	    (ec->rx_coalesce_usecs == 2))

		return -EINVAL;



	if (ec->rx_coalesce_usecs <= 3) {

		adapter->itr = 20000;

		adapter->itr_setting = ec->rx_coalesce_usecs;

	} else {

		adapter->itr = (1000000 / ec->rx_coalesce_usecs);

		adapter->itr_setting = adapter->itr & ~3;

	}



	if (adapter->itr_setting != 0)

		ew32(ITR, 1000000000 / (adapter->itr * 256));

	else

		ew32(ITR, 0);



	return 0;

}



static int e1000_nway_reset(struct net_device *netdev)

{

	struct e1000_adapter *adapter = netdev_priv(netdev);
@@ -1979,6 +2026,8 @@ static const struct ethtool_ops e1000_ethtool_ops = { 
	.phys_id                = e1000_phys_id,

	.get_ethtool_stats      = e1000_get_ethtool_stats,

	.get_sset_count         = e1000_get_sset_count,

	.get_coalesce           = e1000_get_coalesce,

	.set_coalesce           = e1000_set_coalesce,

};



void e1000_set_ethtool_ops(struct net_device *netdev)