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Subject: Re: [PATCH 2/4] extcon: extcon-max14577: Fix potential work-queue
 cancellation race
To:     Matti Vaittinen <matti.vaittinen@fi.rohmeurope.com>,
        Matti Vaittinen <mazziesaccount@gmail.com>
Cc:     Chanwoo Choi <cw00.choi@samsung.com>,
        Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>,
        MyungJoo Ham <myungjoo.ham@samsung.com>,
        Hans de Goede <hdegoede@redhat.com>,
        Marek Szyprowski <m.szyprowski@samsung.com>,
        linux-kernel@vger.kernel.org
References: <cover.1620633360.git.matti.vaittinen@fi.rohmeurope.com>
 <70dfbe28725bac3383f77d02037f4f7f37839989.1620633360.git.matti.vaittinen@fi.rohmeurope.com>
From:   Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
Message-ID: <9a706f57-6c2a-6680-e24b-ff00fe15b95f@canonical.com>
Date:   Mon, 10 May 2021 10:13:01 -0400
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On 10/05/2021 04:11, Matti Vaittinen wrote:
> The extcon IRQ schedules a work item. IRQ is requested using devm while
> WQ is cancelld at remove(). This mixing of devm and manual unwinding has
> potential case where the WQ has been emptied (.remove() was ran) but
> devm unwinding of IRQ was not yet done. It is possible the IRQ is triggered
> at this point scheduling new work item to the already flushed queue.
> 
> Use new devm_work_autocancel() to remove the remove() and to kill the bug.
> 
> Signed-off-by: Matti Vaittinen <matti.vaittinen@fi.rohmeurope.com>
> ---
> 
> Please note that the change is compile-tested only. All proper testing is
> highly appreciated.
> ---
>  drivers/extcon/extcon-max14577.c | 16 +++++-----------
>  1 file changed, 5 insertions(+), 11 deletions(-)
> 

I don't have the HW anymore for this testing, but looks good:

Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>


Best regards,
Krzysztof