From: Mike Marciniszyn <mike.marciniszyn@xxxxxxxxxxxxxxxxxxxx> It is possible for the primary IPoIB network device associated with any RDMA device to fail to join certain multicast groups preventing IPv6 neighbor discovery and possibly other network ULPs from working correctly. The IPv4 broadcast group is not affected as the IPoIB network device handles joining that multicast group directly. This is because the primary IPoIB network device uses the pkey at ndex 0 in the associated RDMA device's pkey table. Anytime the pkey value of index 0 changes, the primary IPoIB network device automatically modifies it's broadcast address (i.e. /sys/class/net/[ib0]/broadcast), since the broadcast address includes the pkey value, and then bounces carrier. This includes initial pkey assignment, such as when the pkey at index 0 transitions from the opa default of invalid (0x0000) to some value such as the OPA default pkey for Virtual Fabric 0: 0x8001 or when the fabric manager is restarted with a configuration change causing the pkey at index 0 to change. Many network ULPs are not sensitive to the carrier bounce and are not expecting the broadcast address to change including the linux IPv6 stack. This problem does not affect IPoIB child network devices as their pkey value is constant for all time. To mitigate this issue, change the default pkey in at index 0 to 0x8001 to cover the predominant case and avoid issues as ipoib comes up and the FM sweeps. At some point, ipoib multicast support should automatically fix non-broadcast addresses as it does with the primary broadcast address. Fixes: 7724105686e7 ("IB/hfi1: add driver files") Suggested-by: Josh Collier <josh.d.collier@xxxxxxxxx> Signed-off-by: Mike Marciniszyn <mike.marciniszyn@xxxxxxxxxxxxxxxxxxxx> Signed-off-by: Dennis Dalessandro <dennis.dalessandro@xxxxxxxxxxxxxxxxxxxx> --- drivers/infiniband/hw/hfi1/init.c | 7 +------ 1 file changed, 1 insertion(+), 6 deletions(-) diff --git a/drivers/infiniband/hw/hfi1/init.c b/drivers/infiniband/hw/hfi1/init.c index 0986aa0..34106e5 100644 --- a/drivers/infiniband/hw/hfi1/init.c +++ b/drivers/infiniband/hw/hfi1/init.c @@ -650,12 +650,7 @@ void hfi1_init_pportdata(struct pci_dev *pdev, struct hfi1_pportdata *ppd, ppd->pkeys[default_pkey_idx] = DEFAULT_P_KEY; ppd->part_enforce |= HFI1_PART_ENFORCE_IN; - - if (loopback) { - dd_dev_err(dd, "Faking data partition 0x8001 in idx %u\n", - !default_pkey_idx); - ppd->pkeys[!default_pkey_idx] = 0x8001; - } + ppd->pkeys[0] = 0x8001; INIT_WORK(&ppd->link_vc_work, handle_verify_cap); INIT_WORK(&ppd->link_up_work, handle_link_up); External recipient