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| author | Stefan Richter <stefanr@s5r6.in-berlin.de> | 2007-04-03 23:55:40 +0200 |
|---|---|---|
| committer | Stefan Richter <stefanr@s5r6.in-berlin.de> | 2007-04-30 00:00:31 +0200 |
| commit | 17bab407d54ba1320d71a45641ecffc33bd331c1 (patch) | |
| tree | f22e2a2cf6daaee3d5461d12f162083ba11d38da /drivers/ieee1394/eth1394.c | |
| parent | f982e5ffcfa9d0a2480d0b8261bd11521f3a1994 (diff) | |
| download | linux-17bab407d54ba1320d71a45641ecffc33bd331c1.tar.bz2 | |
ieee1394: eth1394: allow MTU bigger than 1500
RFC 2734 says: "IP-capable nodes may operate with an MTU size larger
than the default [1500 octets], but the means by which a larger MTU is
configured are beyond the scope of this document."
Allow users to set an MTU bigger than 1500.
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Diffstat (limited to 'drivers/ieee1394/eth1394.c')
| -rw-r--r-- | drivers/ieee1394/eth1394.c | 34 |
1 files changed, 19 insertions, 15 deletions
diff --git a/drivers/ieee1394/eth1394.c b/drivers/ieee1394/eth1394.c index 8f19f5b77a59..aee82922e6b7 100644 --- a/drivers/ieee1394/eth1394.c +++ b/drivers/ieee1394/eth1394.c @@ -136,9 +136,6 @@ static const int hdr_type_len[] = { sizeof(struct eth1394_sf_hdr) }; -/* For now, this needs to be 1500, so that XP works with us */ -#define ETH1394_DATA_LEN ETH_DATA_LEN - static const u16 eth1394_speedto_maxpayload[] = { /* S100, S200, S400, S800, S1600, S3200 */ 512, 1024, 2048, 4096, 4096, 4096 @@ -262,17 +259,27 @@ static void ether1394_tx_timeout(struct net_device *dev) ether1394_host_reset(host); } +static inline int ether1394_max_mtu(struct hpsb_host* host) +{ + return (1 << (host->csr.max_rec + 1)) + - sizeof(union eth1394_hdr) - ETHER1394_GASP_OVERHEAD; +} + static int ether1394_change_mtu(struct net_device *dev, int new_mtu) { - int max_rec = - ((struct eth1394_priv *)netdev_priv(dev))->host->csr.max_rec; + int max_mtu; - if (new_mtu < 68 || - new_mtu > ETH1394_DATA_LEN || - new_mtu > (1 << (max_rec + 1)) - sizeof(union eth1394_hdr) - - ETHER1394_GASP_OVERHEAD) + if (new_mtu < 68) return -EINVAL; + max_mtu = ether1394_max_mtu( + ((struct eth1394_priv *)netdev_priv(dev))->host); + if (new_mtu > max_mtu) { + ETH1394_PRINT(KERN_INFO, dev->name, + "Local node constrains MTU to %d\n", max_mtu); + return -ERANGE; + } + dev->mtu = new_mtu; return 0; } @@ -476,13 +483,10 @@ static void ether1394_reset_priv(struct net_device *dev, int set_mtu) max_speed = host->speed[i]; priv->bc_sspd = max_speed; - /* We'll use our maximum payload as the default MTU */ if (set_mtu) { - int max_payload = 1 << (host->csr.max_rec + 1); - - dev->mtu = min(ETH1394_DATA_LEN, - (int)(max_payload - sizeof(union eth1394_hdr) - - ETHER1394_GASP_OVERHEAD)); + /* Use the RFC 2734 default 1500 octets or the maximum payload + * as initial MTU */ + dev->mtu = min(1500, ether1394_max_mtu(host)); /* Set our hardware address while we're at it */ memcpy(dev->dev_addr, &guid, sizeof(u64)); |