[SRU][[X,Z,A]][PATCH 0/2] Fixes for LP:1730550

[Joseph Salisbury]

BugLink: http://bugs.launchpad.net/bugs/1730550

== SRU Justification ==
This issue was first reported on the netdev email list by Lennart Sorensen:
https://www.mail-archive.com/netdev@vger.kernel.org/msg178170.html

Commit 16ecba59bc333d6282ee057fb02339f77a880beb causes link drops on the 82574L under heavy load.

"Unfortunately this commit changed the driver to assume
that the Other Causes interrupt can only mean link state change and
hence sets the flag that (unfortunately) means both link is down and link
state should be checked. Since this now happens 3000 times per second,
the chances of it happening while the watchdog_task is checking the link
state becomes pretty high, and it if does happen to coincice, then the
watchdog_task will reset the adapter, which causes a real loss of link."

The original reported experienced this issue on a Supermicro X7SPA-HF-D525 server board. 
However, the bug is now seen on many servers running X9DBL-1F server boards. 

This bug is fixed by commits 19110cfbb34 and 4aea7a5c5e9, which were both added
to mainline in v4.15-rc1.

The commit that introduced this bug,16ecba5, was added to mainlien in v4.5-rc1.  However,
Xenial recived this commit as well as commit 531ff577a.  Bionic master-next does not need
these commits, since it got them via bug 1735843 and the 4.14.3 updates. 

== Fixes ==
19110cfbb34 ("e1000e: Separate signaling for link check/link up")
4aea7a5c5e9 ("e1000e: Avoid receiver overrun interrupt bursts")

== Regression Potential ==
These commits are specific to e1000.

== Test Case ==
A test kernel was built with these patches and tested by the original bug reporter.
The bug reporter states the test kernel resolved the bug.


Benjamin Poirier (2):
  e1000e: Separate signaling for link check/link up
  e1000e: Avoid receiver overrun interrupt bursts

 drivers/net/ethernet/intel/e1000e/defines.h |  1 +
 drivers/net/ethernet/intel/e1000e/mac.c     | 11 ++++++---
 drivers/net/ethernet/intel/e1000e/netdev.c  | 35 +++++++++++++++++++++--------
 3 files changed, 35 insertions(+), 12 deletions(-)

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2.7.4