svn commit: r364878 - stable/12/sys/dev/e1000

[Vincenzo Maffione]

Author: vmaffione
Date: Thu Aug 27 19:12:39 2020
New Revision: 364878
URL: https://svnweb.freebsd.org/changeset/base/364878

Log:
  MFC r363995
  
  em(4): honor vlanhwtag offload
  
  The FreeBSD em driver fails to properly reset the VME flag
  in the e1000 CTRL register oneg the following ifconfig command
  
      ifconfig em1 -vlanhwtag
  
  Tested on the e1000 device emulated by QEMU, and on a real
  NIC (chip=0x10d38086).
  
  PR:     236584
  Submitted by:    murat at sunnyvalley.io
  Reported by:     murat at sunnyvalley.io
  Differential Revision:  https://reviews.freebsd.org/D25286

Modified:
  stable/12/sys/dev/e1000/if_em.c
Directory Properties:
  stable/12/   (props changed)

Modified: stable/12/sys/dev/e1000/if_em.c
==============================================================================
--- stable/12/sys/dev/e1000/if_em.c	Thu Aug 27 17:46:13 2020	(r364877)
+++ stable/12/sys/dev/e1000/if_em.c	Thu Aug 27 19:12:39 2020	(r364878)
@@ -1330,6 +1330,11 @@ em_if_init(if_ctx_t ctx)
 			ctrl |= E1000_CTRL_VME;
 			E1000_WRITE_REG(&adapter->hw, E1000_CTRL, ctrl);
 		}
+	} else {
+		u32 ctrl;
+		ctrl = E1000_READ_REG(&adapter->hw, E1000_CTRL);
+		ctrl &= ~E1000_CTRL_VME;
+		E1000_WRITE_REG(&adapter->hw, E1000_CTRL, ctrl);
 	}
 
 	/* Don't lose promiscuous settings */