[PATCH 0/1][SRU][H][Unstable][OEM-5.10] An recursive locking in igb and igc drivers

[AceLan Kao]

From: "Chia-Lin Kao (AceLan)" <acelan.kao at canonical.com>

BugLink: https://bugs.launchpad.net/bugs/1926564

[Impact]
The rtnl_lock() has been called in rtnetlink_rcv_msg(), and then in
__dev_open() it calls pm_runtime_resume() to resume devices, and in
some devices' resume function(igb_resum,igc_resume) they calls rtnl_lock()
again. That leads to a recursive lock.

This issue is introduced by below commit since v5.9-rc1
bd869245a3dc net: core: try to runtime-resume detached device in __dev_open

[Fix]
This commit currently is still under discussion fixes the issue.
https://lkml.org/lkml/2021/4/20/123

[Test]
Verified on Dell Precision workstations.

[Where problems could occur]
The patch is pretty straightforward, no problems could occur by this change.

Chia-Lin Kao (AceLan) (1):
  net: called rtnl_unlock() before runpm resumes devices

 net/core/dev.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

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2.25.1