Re: [Intel-wired-lan] [iwl-next v4 2/2] igc: Link queues to NAPI instances

[Joe Damato <jdamato@fastly.com>]

On Mon, Oct 28, 2024 at 11:53:55AM -0700, Jacob Keller wrote:
> 
> 
> On 10/28/2024 9:00 AM, Joe Damato wrote:
> > 
> > I see, so it looks like there is:
> >    - resume
> >    - runtime_resume
> > 
> > The bug I am reintroducing is runtime_resume already holding RTNL
> > before my added call to rtnl_lock.
> > 
> > OK.
> > 
> > Does resume also hold rtnl before the driver's igc_resume is called?
> > I am asking because I don't know much about how PM works.
> > 
> > If resume does not hold RTNL (but runtime resume does, as the bug
> > you pointed out shows), it seems like a wrapper can be added to tell
> > the code whether rtnl should be held or not based on which resume is
> > happening.
> > 
> > Does anyone know if: resume (not runtime_resume) already holds RTNL?
> > I'll try to take a look and see, but I am not very familiar with PM.
> 
> I believe the resume doesn't hold RTNL, as its part of the core device
> code, which is not networking specific. It shouldn't be acquiring RTNL
> since that is a network specific lock.
> 
> I believe the code you posted as v5 should resolve this, and makes sense
> to me.
> 
> Thanks for digging into this :)

No problem; sorry for all the back and forth on this one and I
really appreciate your patience and reviews.

Thanks,
Joe