[(RFC) PATCH ] be2net: Allow a VF to use physical link state.

* [(RFC) PATCH ] be2net: Allow a VF to use physical link state.
@ 2020-06-09  0:00 David Wilder
  2020-06-09 21:58 ` Jakub Kicinski
  0 siblings, 1 reply; 4+ messages in thread
From: David Wilder @ 2020-06-09  0:00 UTC (permalink / raw)
  To: netdev; +Cc: wilder, ajit.khaparde, sriharsha.basavapatna, somnath.kotur

Hyper-visors owning a PF are allowed by Emulex specification to provide
a VF with separate physical and/or logical link states. However, on
linux, a VF driver must chose one or the other.

My scenario is a proprietary driver controlling the PF, be2net is the VF.
When I do a physical cable pull test the PF sends a link event
notification to the VF with the "physical" link status but this is
ignored in be2net (see be_async_link_state_process() ).

The PF is reporting the adapter type as:
0xe228   /* Device id for VF in Lancer */

I added a module parameter "use_pf_link_state". When set the VF should
ignore logical link state and use the physical link state.

However I have an issue making this work.  When the cable is pulled I
see two link statuses reported:
[1706100.767718] be2net 8002:01:00.0 eth1: Link is Down
[1706101.189298] be2net 8002:01:00.0 eth1: Link is Up

be_link_status_update() is called twice, the first with the physical link
status called from be_async_link_state_process(), and the second with the
logical link status from be_get_link_ksettings().

I am unsure why be_async_link_state_process() is called from
be_get_link_ksettings(), it results in multiple link state changes
(even in the un-patched case). If I eliminate this call then it works.
But I am un-sure of this change.

Signed-off-by: David Wilder <dwilder@us.ibm.com>
---
 drivers/net/ethernet/emulex/benet/be_cmds.c    | 9 ++++++++-
 drivers/net/ethernet/emulex/benet/be_ethtool.c | 2 --
 drivers/net/ethernet/emulex/benet/be_main.c    | 4 ++++
 3 files changed, 12 insertions(+), 3 deletions(-)

diff --git a/drivers/net/ethernet/emulex/benet/be_cmds.c b/drivers/net/ethernet/emulex/benet/be_cmds.c
index 701c12c..52934b2 100644
--- a/drivers/net/ethernet/emulex/benet/be_cmds.c
+++ b/drivers/net/ethernet/emulex/benet/be_cmds.c
@@ -278,6 +278,8 @@ static int be_mcc_compl_process(struct be_adapter *adapter,
 	return compl->status;
 }
 
+extern int use_pf_link_state;
+
 /* Link state evt is a string of bytes; no need for endian swapping */
 static void be_async_link_state_process(struct be_adapter *adapter,
 					struct be_mcc_compl *compl)
@@ -288,13 +290,18 @@ static void be_async_link_state_process(struct be_adapter *adapter,
 	/* When link status changes, link speed must be re-queried from FW */
 	adapter->phy.link_speed = -1;
 
+	if (use_pf_link_state &&
+	    evt->port_link_status & LOGICAL_LINK_STATUS_MASK)
+		return;
+
 	/* On BEx the FW does not send a separate link status
 	 * notification for physical and logical link.
 	 * On other chips just process the logical link
 	 * status notification
 	 */
 	if (!BEx_chip(adapter) &&
-	    !(evt->port_link_status & LOGICAL_LINK_STATUS_MASK))
+	    !(evt->port_link_status & LOGICAL_LINK_STATUS_MASK) &&
+	    !use_pf_link_state)
 		return;
 
 	/* For the initial link status do not rely on the ASYNC event as
diff --git a/drivers/net/ethernet/emulex/benet/be_ethtool.c b/drivers/net/ethernet/emulex/benet/be_ethtool.c
index d6ed1d9..fd91d63 100644
--- a/drivers/net/ethernet/emulex/benet/be_ethtool.c
+++ b/drivers/net/ethernet/emulex/benet/be_ethtool.c
@@ -618,8 +618,6 @@ static int be_get_link_ksettings(struct net_device *netdev,
 	if (adapter->phy.link_speed < 0) {
 		status = be_cmd_link_status_query(adapter, &link_speed,
 						  &link_status, 0);
-		if (!status)
-			be_link_status_update(adapter, link_status);
 		cmd->base.speed = link_speed;
 
 		status = be_cmd_get_phy_info(adapter);
diff --git a/drivers/net/ethernet/emulex/benet/be_main.c b/drivers/net/ethernet/emulex/benet/be_main.c
index a7ac23a..1020be6 100644
--- a/drivers/net/ethernet/emulex/benet/be_main.c
+++ b/drivers/net/ethernet/emulex/benet/be_main.c
@@ -36,6 +36,10 @@
 module_param(rx_frag_size, ushort, 0444);
 MODULE_PARM_DESC(rx_frag_size, "Size of a fragment that holds rcvd data.");
 
+unsigned int use_pf_link_state;
+module_param(use_pf_link_state, uint, 0444);
+MODULE_PARM_DESC(use_pf_link_state, "Use physical link state");
+
 /* Per-module error detection/recovery workq shared across all functions.
  * Each function schedules its own work request on this shared workq.
  */
-- 
1.8.3.1


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