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Date: Mon, 15 Jul 2013 14:35:23 +0200
From: Lars-Peter Clausen <lars@metafoo.de>
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To: Oleksandr Kravchenko <o.v.kravchenko@globallogic.com>
CC: Oleksandr Kravchenko <x0199363@ti.com>, linux-iio@vger.kernel.org,
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        srinivas.pandruvada@intel.com, devicetree-discuss@lists.ozlabs.org
Subject: Re: [PATCH] iio: add APDS9300 ambilent light sensor driver
References: <1373461729-11261-1-git-send-email-x0199363@ti.com> <51E03720.1010806@metafoo.de> <CAGH3drqEPxW=QwadCLj=ZOQe0gp_c7mdSiNQnq1_-BMKL9CgJw@mail.gmail.com>
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On 07/15/2013 02:27 PM, Oleksandr Kravchenko wrote:
> Thank you for review! But I don't completely understand one of your comment:
> 
>>> +static int als_probe(struct i2c_client *client, const struct i2c_device_id *id)
> [...]
>>> +     if (client->irq) {
>>> +             ret = devm_request_threaded_irq(&client->dev, client->irq,
>>> +                             NULL, als_interrupt_handler,
>>> +                             IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
>>> +                             ALS_IRQ_NAME, indio_dev);
>>
>> This is a bit racy, you access memory in the irq handler that is freed
>> before the irq is freed.
> 
> Do you mean than that indio_dev may be used in interrupt handler after
> iio_device_free(indio_dev) called in als_remove() function?
> 
> If so, can I use disable_irq() in als_remove() before iio_device_free()
> to avoid this problem?
> 

Just add a devm_iio_device_alloc() and use that, instead of trying to bodch
around the issue.