linux-kernel - Re: [PATCH] Input: pwm-beeper - fix: scheduling while atomic

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Message-ID: <574411B5.2010407@gmx.at>
Date:	Tue, 24 May 2016 10:32:53 +0200
From:	Manfred Schlaegl <manfred.schlaegl@....at>
To:	Dmitry Torokhov <dmitry.torokhov@...il.com>
Cc:	Thierry Reding <thierry.reding@...il.com>,
	Manfred Schlaegl <manfred.schlaegl@...zinger.com>,
	Luis de Bethencourt <luis@...ethencourt.com>,
	Olivier Sobrie <olivier@...rie.be>,
	linux-input@...r.kernel.org, linux-kernel@...r.kernel.org,
	Greg Kroah-Hartman <gregkh@...uxfoundation.org>
Subject: Re: [PATCH] Input: pwm-beeper - fix: scheduling while atomic

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