From mboxrd@z Thu Jan  1 00:00:00 1970
From: Johan Hovold <johan-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>
Subject: Re: [PATCH 2/4] usb: musb: Fix sleeping function called from invalid
 context for hdrc glue
Date: Wed, 9 Nov 2016 16:50:12 +0100
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To: Tony Lindgren <tony-4v6yS6AI5VpBDgjK7y7TUQ@public.gmane.org>
Cc: Johan Hovold <johan-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>, Bin Liu <b-liu-l0cyMroinI0@public.gmane.org>, Boris Brezillon <boris.brezillon-wi1+55ScJUtKEb57/3fJTNBPR1lH4CV8@public.gmane.org>, Greg Kroah-Hartman <gregkh-hQyY1W1yCW8ekmWlsbkhG0B+6BGkLq7r@public.gmane.org>, Andreas Kemnade <andreas-cLv4Z9ELZ06ZuzBka8ofvg@public.gmane.org>, Felipe Balbi <balbi-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>, George Cherian <george.cherian-l0cyMroinI0@public.gmane.org>, Kishon Vijay Abraham I <kishon-l0cyMroinI0@public.gmane.org>, Ivaylo Dimitrov <ivo.g.dimitrov.75-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>, Ladislav Michl <ladis-6z/3iImG2C8G8FEW9MqTrA@public.gmane.org>, Laurent Pinchart <laurent.pinchart-ryLnwIuWjnjg/C1BVhZhaw@public.gmane.org>, Sergei Shtylyov <sergei.shtylyov-M4DtvfQ/ZS1MRgGoP+s0PdBPR1lH4CV8@public.gmane.org>, linux-usb-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-omap-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
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On Wed, Nov 09, 2016 at 08:34:10AM -0700, Tony Lindgren wrote:
> * Tony Lindgren <tony-4v6yS6AI5VpBDgjK7y7TUQ@public.gmane.org> [161108 18:26]:
> > * Johan Hovold <johan-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org> [161108 12:03]:
> > +int musb_queue_resume_work(struct musb *musb,
> > +			   int (*callback)(struct musb *musb, void *data),
> > +			   void *data)
> > +{
> > +	struct musb_pending_work *w;
> > +	unsigned long flags;
> > +	int error;
> > +
> > +	if (WARN_ON(!callback))
> > +		return -EINVAL;
> > +
> > +	if (pm_runtime_active(musb->controller))
> > +		return callback(musb, data);
> > +
> > +	w = devm_kzalloc(musb->controller, sizeof(*w), GFP_ATOMIC);
> > +	if (!w)
> > +		return -ENOMEM;
> > +
> > +	w->callback = callback;
> > +	w->data = data;
> > +	spin_lock_irqsave(&musb->list_lock, flags);
> > +	if (musb->is_runtime_suspended) {
> > +		list_add_tail(&w->node, &musb->pending_list);
> > +		error = 0;
> > +	} else {
> > +		dev_err(musb->controller, "could not add resume work %p\n",
> > +			callback);
> > +		devm_kfree(musb->controller, w);
> > +		error = -EINPROGRESS;
> > +	}
> > +	spin_unlock_irqrestore(&musb->list_lock, flags);
> > +
> > +	if (pm_runtime_active(musb->controller))
> > +		return musb_run_resume_work(musb);
> > +
> > +	return error;
> > +}
> 
> Hmm I think we can also leave out musb_run_resume_work() at the end,
> we should not hit that case any longer.

That seems to be the case, yes. But we still need to process that work
somehow also when racing with runtime_resume() (e.g. here or at every
call site).

Johan
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