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Subject: Re: [PATCH] Input: pwm-beeper - fix: scheduling while atomic
To: Dmitry Torokhov <dmitry.torokhov@gmail.com>
References: <56C4735E.6020300@gmx.at> <20160222194639.GD26177@dtor-ws>
 <20160512121852.GB26824@ulmo.ba.sec> <5735F4E3.20008@gmx.at>
 <573C8761.9070601@gmx.at> <20160520165918.GE14951@dtor-ws>
Cc: Thierry Reding <thierry.reding@gmail.com>,
        Manfred Schlaegl <manfred.schlaegl@ginzinger.com>,
        Luis de Bethencourt <luis@debethencourt.com>,
        Olivier Sobrie <olivier@sobrie.be>, linux-input@vger.kernel.org,
        linux-kernel@vger.kernel.org,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>
From: Manfred Schlaegl <manfred.schlaegl@gmx.at>
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Date: Tue, 24 May 2016 10:32:53 +0200
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On 2016-05-20 18:59, Dmitry Torokhov wrote:
> Hi Manfred,
> 
> On Wed, May 18, 2016 at 05:16:49PM +0200, Manfred Schlaegl wrote:
>> @@ -133,6 +149,8 @@ static int pwm_beeper_remove(struct platform_device *pdev)
>>  {
>>  	struct pwm_beeper *beeper = platform_get_drvdata(pdev);
>>  
>> +	cancel_work_sync(&beeper->work);
>> +
>>  	input_unregister_device(beeper->input);
> 
> This is racy, request to play may come in after cancel_work_sync()
> returns but before we unregistered input device. I think you want the
> version below.
> 

Hi Dmitry,

yes you are right. Thank you for your feedback.
I also see that point, but I think it would be a simpler change just
to cancel the worker after unregistering the device (to reorder 
cancel_work_sync and input_unregister_device).

Patch will follow shortly.

What do you think?

Sincerely,
Manfred