diff options
| author | stephen hemminger <shemminger@vyatta.com> | 2011-11-17 14:37:23 +0000 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2011-11-17 21:43:57 -0500 |
| commit | 738a849c8eef4787a526d95763f985b8c1cb68e4 (patch) | |
| tree | 8e172b7f8b7d02929cc2045b7bd26e66d4248b24 /drivers | |
| parent | 4a8bb7e27fbb68da888b55f26defd2855225b2d5 (diff) | |
sky2: enforce minimum ring size
The hardware has a restriction that the minimum ring size possible
is 128. The number of elements used is controlled by tx_pending and
the overall number of elements in the ring tx_ring_size, therefore it
is okay to limit the number of elements in use to a small value (63)
but still provide a bigger ring.
Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/net/ethernet/marvell/sky2.c | 14 |
1 files changed, 12 insertions, 2 deletions
diff --git a/drivers/net/ethernet/marvell/sky2.c b/drivers/net/ethernet/marvell/sky2.c index 539de09cffc..d9968717770 100644 --- a/drivers/net/ethernet/marvell/sky2.c +++ b/drivers/net/ethernet/marvell/sky2.c @@ -4088,6 +4088,16 @@ static int sky2_set_coalesce(struct net_device *dev, return 0; } +/* + * Hardware is limited to min of 128 and max of 2048 for ring size + * and rounded up to next power of two + * to avoid division in modulus calclation + */ +static unsigned long roundup_ring_size(unsigned long pending) +{ + return max(128ul, roundup_pow_of_two(pending+1)); +} + static void sky2_get_ringparam(struct net_device *dev, struct ethtool_ringparam *ering) { @@ -4115,7 +4125,7 @@ static int sky2_set_ringparam(struct net_device *dev, sky2->rx_pending = ering->rx_pending; sky2->tx_pending = ering->tx_pending; - sky2->tx_ring_size = roundup_pow_of_two(sky2->tx_pending+1); + sky2->tx_ring_size = roundup_ring_size(sky2->tx_pending); return sky2_reattach(dev); } @@ -4709,7 +4719,7 @@ static __devinit struct net_device *sky2_init_netdev(struct sky2_hw *hw, spin_lock_init(&sky2->phy_lock); sky2->tx_pending = TX_DEF_PENDING; - sky2->tx_ring_size = roundup_pow_of_two(TX_DEF_PENDING+1); + sky2->tx_ring_size = roundup_ring_size(TX_DEF_PENDING); sky2->rx_pending = RX_DEF_PENDING; hw->dev[port] = dev; |