| Message ID | 1561655353-17114-1-git-send-email-tlfalcon@linux.ibm.com |
|---|---|
| State | Changes Requested |
| Delegated to: | David Miller |
| Headers | show |
| Series | [net] net/ibmvnic: Report last valid speed and duplex values to ethtool | expand |
On Thu, Jun 27, 2019 at 12:09:13PM -0500, Thomas Falcon wrote: > This patch resolves an issue with sensitive bonding modes > that require valid speed and duplex settings to function > properly. Currently, the adapter will report that device > speed and duplex is unknown if the communication link > with firmware is unavailable. Dumb question. If you cannot communicate with the firmware, isn't the device FUBAR? So setting the LACP port to disabled is the correct things to do. Andrew
On 6/27/19 12:57 PM, Andrew Lunn wrote: > On Thu, Jun 27, 2019 at 12:09:13PM -0500, Thomas Falcon wrote: >> This patch resolves an issue with sensitive bonding modes >> that require valid speed and duplex settings to function >> properly. Currently, the adapter will report that device >> speed and duplex is unknown if the communication link >> with firmware is unavailable. > Dumb question. If you cannot communicate with the firmware, isn't the > device FUBAR? So setting the LACP port to disabled is the correct > things to do. > > Andrew > Yes, I think that is correct too. The problem is that the link is only down temporarily. In this case - we are testing with a pseries logical partition - the partition is migrated to another server. The driver must wait for a signal from the hypervisor to resume operation with the new device. Once it resumes, we see that the device reboots and gets correct speed settings, but the port flag (AD_LACP_PORT_ENABLED) is still cleared. Tom
From: Thomas Falcon <tlfalcon@linux.ibm.com> Date: Thu, 27 Jun 2019 12:09:13 -0500 > This patch resolves an issue with sensitive bonding modes > that require valid speed and duplex settings to function > properly. Currently, the adapter will report that device > speed and duplex is unknown if the communication link > with firmware is unavailable. This decision can break LACP > configurations if the timing is right. > > For example, if invalid speeds are reported, the slave > device's link state is set to a transitional "fail" state > and the LACP port is disabled. However, if valid speeds > are reported later but the link state has not been altered, > the LACP port will remain disabled. If the link state then > transitions back to "up" from "fail," it results in a state > such that the slave reports valid speed/duplex and is up, > but the LACP port will remain disabled. > > Workaround this by reporting the last recorded speed > and duplex settings unless the device has never been > activated. In that case or when the hypervisor gives > invalid values, continue to report unknown speed or > duplex to ethtool. > > Signed-off-by: Thomas Falcon <tlfalcon@linux.ibm.com> Like Andrew, I have my conerns about this. If the firmware is unavailable, the link is effectively down. So you should report link down and unknown link parameters. Bonding and LACP should do the right thing when the firwmare is reachable again after the migration and the link goes back up. If bonding/LACP isn't doing that, then the bug is there.
diff --git a/drivers/net/ethernet/ibm/ibmvnic.c b/drivers/net/ethernet/ibm/ibmvnic.c index 3da6800..7c14e33 100644 --- a/drivers/net/ethernet/ibm/ibmvnic.c +++ b/drivers/net/ethernet/ibm/ibmvnic.c @@ -2276,10 +2276,8 @@ static int ibmvnic_get_link_ksettings(struct net_device *netdev, int rc; rc = send_query_phys_parms(adapter); - if (rc) { - adapter->speed = SPEED_UNKNOWN; - adapter->duplex = DUPLEX_UNKNOWN; - } + if (rc) + netdev_warn(netdev, "Device query of current speed and duplex settings failed; reported values may be stale.\n"); cmd->base.speed = adapter->speed; cmd->base.duplex = adapter->duplex; cmd->base.port = PORT_FIBRE; @@ -4834,6 +4832,8 @@ static int ibmvnic_probe(struct vio_dev *dev, const struct vio_device_id *id) dev_set_drvdata(&dev->dev, netdev); adapter->vdev = dev; adapter->netdev = netdev; + adapter->speed = SPEED_UNKNOWN; + adapter->duplex = DUPLEX_UNKNOWN; ether_addr_copy(adapter->mac_addr, mac_addr_p); ether_addr_copy(netdev->dev_addr, adapter->mac_addr);
This patch resolves an issue with sensitive bonding modes that require valid speed and duplex settings to function properly. Currently, the adapter will report that device speed and duplex is unknown if the communication link with firmware is unavailable. This decision can break LACP configurations if the timing is right. For example, if invalid speeds are reported, the slave device's link state is set to a transitional "fail" state and the LACP port is disabled. However, if valid speeds are reported later but the link state has not been altered, the LACP port will remain disabled. If the link state then transitions back to "up" from "fail," it results in a state such that the slave reports valid speed/duplex and is up, but the LACP port will remain disabled. Workaround this by reporting the last recorded speed and duplex settings unless the device has never been activated. In that case or when the hypervisor gives invalid values, continue to report unknown speed or duplex to ethtool. Signed-off-by: Thomas Falcon <tlfalcon@linux.ibm.com> --- drivers/net/ethernet/ibm/ibmvnic.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-)