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

[Timo Aaltonen]

On 29.4.2021 10.07, AceLan Kao wrote:
> 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(-)
> 

Even though review is still ongoing upstream, we need this version on 
the oem kernel



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t