Bug 168440

Summary: [ixgbe] [patch] ixgbe flow control tunable regression
Product: Base System Reporter: lampa
Component: kernAssignee: freebsd-net (Nobody) <net>
Status: Closed Works As Intended    
Severity: Affects Only Me CC: sbruno
Priority: Normal Keywords: IntelNetworking
Version: 9.0-STABLE   
Hardware: Any   
OS: Any   

Description lampa 2012-05-29 18:00:10 UTC 
hw.ixgbe.flow_control tunable stopped working in the 2.4.5 version, the variable ixgbe_flow_control is not used at all. Previously it was used in ixgbe_set_flowcntl(). Now adapter->fc is used at that place, but it is not initialized properly from the tunable.

Fix: 

Change ixgbe_attach() at line 530:

        /* Get Hardware Flow Control setting */
        hw->fc.requested_mode = ixgbe_fc_full;

to:

        /* Get Hardware Flow Control setting */
        hw->fc.requested_mode = ixgbe_flow_control;

The same problem exists in the ixv driver.
Comment 1 Mark Linimon freebsd_committer freebsd_triage 2014-04-20 03:53:02 UTC 
Responsible Changed
From-To: freebsd-bugs->freebsd-net

reclassify.
Comment 2 Sean Bruno freebsd_committer freebsd_triage 2015-06-30 18:22:26 UTC 
flow control is now a loader tuneable in ixv(4) but it is an SYSCTL in ixgbe(4).

the "fc" sysctl is what you want here.