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Sender: Guenter Roeck <groeck7@gmail.com>
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Date:   Wed, 6 Apr 2022 09:36:10 -0700
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Subject: Re: [PATCH] Bluetooth: hci_qca: Use del_timer_sync() before freeing
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To:     Steven Rostedt <rostedt@goodmis.org>
Cc:     Eric Dumazet <eric.dumazet@gmail.com>,
        LKML <linux-kernel@vger.kernel.org>,
        Marcel Holtmann <marcel@holtmann.org>,
        Johan Hedberg <johan.hedberg@gmail.com>,
        Luiz Augusto von Dentz <luiz.dentz@gmail.com>,
        Ben Young Tae Kim <ytkim@qca.qualcomm.com>,
        Thomas Gleixner <tglx@linutronix.de>
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From:   Guenter Roeck <linux@roeck-us.net>
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On 4/6/22 08:46, Steven Rostedt wrote:
> On Wed, 6 Apr 2022 08:39:07 -0700
> Guenter Roeck <linux@roeck-us.net> wrote:
> 
>>> ie move this destroy_workqueue() up ?
>>>    
>>
>> What prevents the timer code from queueing work into the destroyed
>> workqueue ?
> 
> So we have a chicken verses egg issue here?
> 

Almost looks like it, unless I am missing something. Maybe some flag
is needed to prevent the timer handling code from queuing into the
destroyed workqueue, or the workqueue handler from updating the timer.

Guenter