Re: [GIT PULL] Networking for v5.15

From: Coelho, Luciano
Date: Thu Sep 02 2021 - 05:33:33 EST


On Wed, 2021-09-01 at 21:49 +0200, Johannes Berg wrote:
> On Wed, 2021-09-01 at 12:41 -0700, Jakub Kicinski wrote:
> >
> > >
> > > They all seem to have that same issue, and it looks like the fix would
> > > be to get the RTN lock in iwl_mvm_init_mcc(), but I didn't really look
> > > into it very much.
> > >
> > > This is on my desktop, and I actually don't _use_ the wireless on this
> > > machine. I assume it still works despite the warnings, but they should
> > > get fixed.
> > >
> > > I *don't* see these warnings on my laptop where I actually use
> > > wireless, but that one uses ath10k_pci, so it seems this is purely a
> > > iwlwifi issue.
> > >
> > > I can't be the only one that sees this. Hmm?
> >
> > Mm. Looking thru the recent commits there is a suspicious rtnl_unlock()
> > in commit eb09ae93dabf ("iwlwifi: mvm: load regdomain at INIT stage").
>
> Huh! That's not the version of the commit I remember - it had an
> rtnl_lock() in there too (just before the mutex_lock)?! Looks like that
> should really be there, not sure how/where it got lost along the way.
>
> That unbalanced rtnl_unlock() makes no sense anyway. Wonder why it
> doesn't cause more assertions/problems at that point, clearly it's
> unbalanced. Pretty sure it's missing the rtnl_lock() earlier in the
> function for some reason.
>
> Luca and I will look at it tomorrow, getting late here, sorry.

Right, the reason for this was a rebase damage. We lost the
rtnl_lock() call when I rebased the patch on top of the tree without
iwlmei (which touch this same function).

Sorry for the trouble, I'll send the fix in a sec.

--
Cheers,
Luca.