Re: usb/net/p54: trying to register non-static key in p54_unregister_leds
From: Johannes Berg
Date: Wed Sep 20 2017 - 15:55:14 EST
On Wed, 2017-09-20 at 21:27 +0200, Christian Lamparter wrote:
> It seems this is caused as a result of:
> ÂÂÂÂ-> lock_map_acquire(&work->lockdep_map);
> ÂÂÂÂin flush_work() 
> This was added by:
> commit 0976dfc1d0cd80a4e9dfaf87bd8744612bde475a
> Author: Stephen Boyd <sboyd@xxxxxxxxxxxxxx>
> Date:ÂÂÂFri Apr 20 17:28:50 2012 -0700
> workqueue: Catch more locking problems with flush_work()
Yes, but that doesn't matter.
> Looking at the Stephen's patch, it's clear that it was made
> with "static DECLARE_WORK(work, my_work)" in mind. However
> p54's led_work is "per-device", hence it is stored in the
> devices context p54_common, which is dynamically allocated.
> So, maybe revert Stephen's patch?
I disagree - as the lockdep warning says:
> > INFO: trying to register non-static key.
> > the code is fine but needs lockdep annotation.
> > turning off the locking correctness validator.
What it needs is to actually correctly go through initializing the work
at least once.
Without more information, I can't really say what's going on, but I
assume that something is failing and p54_unregister_leds() is getting
invoked without p54_init_leds() having been invoked, so essentially
it's trying to flush a work that was never initialized?
INIT_DELAYED_WORK() does, after all, initialize the lockdep map
properly via __INIT_WORK().