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From:   Thomas Gleixner <tglx@linutronix.de>
To:     Anna-Maria Behnsen <anna-maria@linutronix.de>
Cc:     LKML <linux-kernel@vger.kernel.org>,
        Linus Torvalds <torvalds@linuxfoundation.org>,
        Steven Rostedt <rostedt@goodmis.org>,
        Peter Zijlstra <peterz@infradead.org>,
        Stephen Boyd <sboyd@kernel.org>,
        Guenter Roeck <linux@roeck-us.net>,
        Andrew Morton <akpm@linux-foundation.org>,
        Julia Lawall <Julia.Lawall@inria.fr>,
        Arnd Bergmann <arnd@arndb.de>,
        Viresh Kumar <viresh.kumar@linaro.org>,
        Marc Zyngier <maz@kernel.org>,
        Marcel Holtmann <marcel@holtmann.org>,
        Johan Hedberg <johan.hedberg@gmail.com>,
        Luiz Augusto von Dentz <luiz.dentz@gmail.com>,
        linux-bluetooth@vger.kernel.org,
        "David S. Miller" <davem@davemloft.net>,
        Eric Dumazet <edumazet@google.com>,
        Jakub Kicinski <kuba@kernel.org>,
        Paolo Abeni <pabeni@redhat.com>, netdev@vger.kernel.org,
        Jacob Keller <jacob.e.keller@intel.com>
Subject: Re: [patch V3 12/17] timers: Silently ignore timers with a NULL
 function
In-Reply-To: <644695b9-f343-7fb7-ed8e-763e5fe3d158@linutronix.de>
References: <20221123201306.823305113@linutronix.de>
 <20221123201625.135055320@linutronix.de>
 <644695b9-f343-7fb7-ed8e-763e5fe3d158@linutronix.de>
Date:   Thu, 24 Nov 2022 09:18:46 +0100
Message-ID: <87zgcgdau1.ffs@tglx>
MIME-Version: 1.0
Content-Type: text/plain
Precedence: bulk

On Thu, Nov 24 2022 at 08:37, Anna-Maria Behnsen wrote:

> On Wed, 23 Nov 2022, Thomas Gleixner wrote:
>
>> Tearing down timers which have circular dependencies to other
>> functionality, e.g. workqueues, where the timer can schedule work and work
>> can arm timers, is not trivial.
>> 
>> In those cases it is desired to shutdown the timer in a way which prevents
>> rearming of the timer. The mechanism to do so is to set timer->function to
>> NULL and use this as an indicator for the timer arming functions to ignore
>> the (re)arm request.
>> 
>> In preparation for that replace the warnings in the relevant code paths
>> with checks for timer->function == NULL. If the pointer is NULLL, then
>
> s/NULLL/NULL

Bah. I should have went to the bar instead of trying to fix this.