diff options
Diffstat (limited to 'hw/net/spapr_llan.c')
| -rw-r--r-- | hw/net/spapr_llan.c | 18 |
1 files changed, 12 insertions, 6 deletions
diff --git a/hw/net/spapr_llan.c b/hw/net/spapr_llan.c index 058908d8d7..d239e4bd7d 100644 --- a/hw/net/spapr_llan.c +++ b/hw/net/spapr_llan.c @@ -385,18 +385,24 @@ static int spapr_vlan_devnode(VIOsPAPRDevice *dev, void *fdt, int node_off) int ret; /* Some old phyp versions give the mac address in an 8-byte - * property. The kernel driver has an insane workaround for this; + * property. The kernel driver (before 3.10) has an insane workaround; * rather than doing the obvious thing and checking the property * length, it checks whether the first byte has 0b10 in the low * bits. If a correct 6-byte property has a different first byte * the kernel will get the wrong mac address, overrunning its * buffer in the process (read only, thank goodness). * - * Here we workaround the kernel workaround by always supplying an - * 8-byte property, with the mac address in the last six bytes */ - memcpy(&padded_mac[2], &vdev->nicconf.macaddr, ETH_ALEN); - ret = fdt_setprop(fdt, node_off, "local-mac-address", - padded_mac, sizeof(padded_mac)); + * Here we return a 6-byte address unless that would break a pre-3.10 + * driver. In that case we return a padded 8-byte address to allow the old + * workaround to succeed. */ + if ((vdev->nicconf.macaddr.a[0] & 0x3) == 0x2) { + ret = fdt_setprop(fdt, node_off, "local-mac-address", + &vdev->nicconf.macaddr, ETH_ALEN); + } else { + memcpy(&padded_mac[2], &vdev->nicconf.macaddr, ETH_ALEN); + ret = fdt_setprop(fdt, node_off, "local-mac-address", + padded_mac, sizeof(padded_mac)); + } if (ret < 0) { return ret; } |