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Re: usb/net/p54: trying to register non-static key in p54_unregister_leds

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On Wed, 2017-09-20 at 21:27 +0200, Christian Lamparter wrote:

> It seems this is caused as a result of:
>     -> lock_map_acquire(&work->lockdep_map);
> 	    lock_map_release(&work->lockdep_map);
> 
>     in flush_work() [0]

Agree.

> This was added by:
> 
> 	commit 0976dfc1d0cd80a4e9dfaf87bd8744612bde475a
> 	Author: Stephen Boyd <sboyd@codeaurora.org>
> 	Date:   Fri 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().

johannes

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usb/net/p54: trying to register non-static key in p54_unregister_leds Andrey Konovalov <andreyknvl@google.com> - 2017-09-20 20:40 +0200
  Re: usb/net/p54: trying to register non-static key in p54_unregister_leds Christian Lamparter <chunkeey@googlemail.com> - 2017-09-20 21:30 +0200
    Re: usb/net/p54: trying to register non-static key in  p54_unregister_leds Johannes Berg <johannes@sipsolutions.net> - 2017-09-20 22:00 +0200
      Re: usb/net/p54: trying to register non-static key in p54_unregister_leds Andrey Konovalov <andreyknvl@google.com> - 2017-09-21 20:30 +0200
        [RESEND] Re: usb/net/p54: trying to register non-static key in p54_unregister_leds Christian Lamparter <chunkeey@googlemail.com> - 2017-09-23 21:40 +0200
          Re: [RESEND] Re: usb/net/p54: trying to register non-static key in  p54_unregister_leds Johannes Berg <johannes@sipsolutions.net> - 2017-09-24 16:20 +0200
          Re: [RESEND] Re: usb/net/p54: trying to register non-static key in p54_unregister_leds Andrey Konovalov <andreyknvl@google.com> - 2017-09-26 17:10 +0200

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