diff options
Diffstat (limited to 'sys/dev/nge')
| -rw-r--r-- | sys/dev/nge/if_nge.c | 64 |
1 files changed, 41 insertions, 23 deletions
diff --git a/sys/dev/nge/if_nge.c b/sys/dev/nge/if_nge.c index ff1b53d..2dcee41 100644 --- a/sys/dev/nge/if_nge.c +++ b/sys/dev/nge/if_nge.c @@ -69,10 +69,22 @@ * via software. This affects the size of certain fields in the DMA * descriptors. * - * As far as I can tell, the 83820 and 83821 are decent chips, marred by - * only one flaw: the RX buffers must be aligned on 64-bit boundaries. - * So far this is the only gigE MAC that I've encountered with this - * requirement. + * There are two bugs/misfeatures in the 83820/83821 that I have + * discovered so far: + * + * - Receive buffers must be aligned on 64-bit boundaries, which means + * you must resort to copying data in order to fix up the payload + * alignment. + * + * - In order to transmit jumbo frames larger than 8170 bytes, you have + * to turn off transmit checksum offloading, because the chip can't + * compute the checksum on an outgoing frame unless it fits entirely + * within the TX FIFO, which is only 8192 bytes in size. If you have + * TX checksum offload enabled and you transmit attempt to transmit a + * frame larger than 8170 bytes, the transmitter will wedge. + * + * To work around the latter problem, TX checksum offload is disabled + * if the user selects an MTU larger than 8152 (8170 - 18). */ #include "vlan.h" @@ -1288,20 +1300,18 @@ static void nge_rxeof(sc) m_adj(m, sizeof(struct ether_header)); /* Do IP checksum checking. */ - if (ifp->if_hwassist) { - if (extsts & NGE_RXEXTSTS_IPPKT) - m->m_pkthdr.csum_flags |= CSUM_IP_CHECKED; - if (!(extsts & NGE_RXEXTSTS_IPCSUMERR)) - m->m_pkthdr.csum_flags |= CSUM_IP_VALID; - if ((extsts & NGE_RXEXTSTS_TCPPKT && - !(extsts & NGE_RXEXTSTS_TCPCSUMERR)) || - (extsts & NGE_RXEXTSTS_UDPPKT && - !(extsts & NGE_RXEXTSTS_UDPCSUMERR))) { - m->m_pkthdr.csum_flags |= - CSUM_DATA_VALID|CSUM_PSEUDO_HDR; - m->m_pkthdr.csum_data = 0xffff; - } - } + if (extsts & NGE_RXEXTSTS_IPPKT) + m->m_pkthdr.csum_flags |= CSUM_IP_CHECKED; + if (!(extsts & NGE_RXEXTSTS_IPCSUMERR)) + m->m_pkthdr.csum_flags |= CSUM_IP_VALID; + if ((extsts & NGE_RXEXTSTS_TCPPKT && + !(extsts & NGE_RXEXTSTS_TCPCSUMERR)) || + (extsts & NGE_RXEXTSTS_UDPPKT && + !(extsts & NGE_RXEXTSTS_UDPCSUMERR))) { + m->m_pkthdr.csum_flags |= + CSUM_DATA_VALID|CSUM_PSEUDO_HDR; + m->m_pkthdr.csum_data = 0xffff; + } #if NVLAN > 0 /* @@ -1721,8 +1731,7 @@ static void nge_init(xsc) * Enable hardware checksum validation for all IPv4 * packets, do not reject packets with bad checksums. */ - if (ifp->if_hwassist) - CSR_WRITE_4(sc, NGE_VLAN_IP_RXCTL, NGE_VIPRXCTL_IPCSUM_ENB); + CSR_WRITE_4(sc, NGE_VLAN_IP_RXCTL, NGE_VIPRXCTL_IPCSUM_ENB); #if NVLAN > 0 /* @@ -1740,8 +1749,7 @@ static void nge_init(xsc) /* * Enable TX IPv4 checksumming on a per-packet basis. */ - if (ifp->if_hwassist) - CSR_WRITE_4(sc, NGE_VLAN_IP_TXCTL, NGE_VIPTXCTL_CSUM_PER_PKT); + CSR_WRITE_4(sc, NGE_VLAN_IP_TXCTL, NGE_VIPTXCTL_CSUM_PER_PKT); #if NVLAN > 0 /* @@ -1856,8 +1864,18 @@ static int nge_ioctl(ifp, command, data) case SIOCSIFMTU: if (ifr->ifr_mtu > NGE_JUMBO_MTU) error = EINVAL; - else + else { ifp->if_mtu = ifr->ifr_mtu; + /* + * Workaround: if the MTU is larger than + * 8152 (TX FIFO size minus 64 minus 18), turn off + * TX checksum offloading. + */ + if (ifr->ifr_mtu == 8152) + ifp->if_hwassist = 0; + else + ifp->if_hwassist = NGE_CSUM_FEATURES; + } break; case SIOCSIFFLAGS: if (ifp->if_flags & IFF_UP) { |
