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Subject: Re: [PATCH 3/4] extcon: extcon-max77693.c: 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>
 <e83fe8359b6b6dfcb0cbc18e8c3efd653971dd44.1620633360.git.matti.vaittinen@fi.rohmeurope.com>
From:   Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
Message-ID: <dadb758c-6130-d2d2-0581-23c33e699574@canonical.com>
Date:   Mon, 10 May 2021 10:16:31 -0400
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On 10/05/2021 04:12, 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 may be possible the IRQ is
> triggered at this point scheduling new work item to the already flushed
> queue.
> 
> According to the input documentation the input device allocated by
> devm_input_allocate_device() does not need to be explicitly unregistered.
> Use the new devm_work_autocancel() and remove the remove() to simplify the
> code.
> 
> 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-max77693.c | 17 +++++------------
>  1 file changed, 5 insertions(+), 12 deletions(-)
> 

Seems correct:

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


Best regards,
Krzysztof