netdev - Re: [PATCH v3] rfkill: Add rfkill-any LED trigger

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Message-ID: <20170105143654.GA21040@ozzy.nask.waw.pl>
Date:   Thu, 5 Jan 2017 15:36:54 +0100
From:   Michał Kępień <kernel@...pniu.pl>
To:     Johannes Berg <johannes@...solutions.net>
Cc:     "David S . Miller" <davem@...emloft.net>,
        Михаил Кринкин 
        <krinkin.m.u@...il.com>, linux-wireless@...r.kernel.org,
        netdev@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH v3] rfkill: Add rfkill-any LED trigger

> On Mon, 2017-01-02 at 13:21 +0100, Johannes Berg wrote:
> > > I'm not super happy with this conditional locking - can't we
> > > instead
> > > defer the necessary work to a workqueue, or so, for purposes of the
> > > LED?
> > 
> > Actually, since you can sleep in here, and do various other things
> > like scheduling etc. this can't even be correct as is - one thread
> > might be in the probe and another might also attempt to do some
> > operations that require the lock but now don't take it.
> 
> Additionally, this doesn't address the "can be called in any context"
> part, only the "even from within rfkill callbacks" part. It's clearly
> still not safe to call this from any context that is not allowed to
> sleep, for example.

Thanks for reviewing.  I will attempt a workqueue-based approach in v4.

-- 
Best regards,
Michał Kępień