netdev - Re: [PATCH v4] can: Convert to runtime

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Message-ID: <54AD6078.80506@pengutronix.de>
Date:	Wed, 07 Jan 2015 17:36:08 +0100
From:	Marc Kleine-Budde <mkl@...gutronix.de>
To:	Sören Brinkmann <soren.brinkmann@...inx.com>
CC:	Kedareswara rao Appana <appana.durga.rao@...inx.com>,
	wg@...ndegger.com, michal.simek@...inx.com,
	grant.likely@...aro.org, linux-can@...r.kernel.org,
	netdev@...r.kernel.org, linux-kernel@...r.kernel.org,
	Kedareswara rao Appana <appanad@...inx.com>
Subject: Re: [PATCH v4] can: Convert to runtime_pm

On 01/07/2015 05:32 PM, Sören Brinkmann wrote:
> On Wed, 2015-01-07 at 05:30PM +0100, Marc Kleine-Budde wrote:
>> On 01/07/2015 04:58 PM, Sören Brinkmann wrote:
>>>> I think you have to convert the _remove() function, too. Have a look at
>>>> the gpio-zynq.c driver:
>>>>
>>>>> static int zynq_gpio_remove(struct platform_device *pdev)
>>>>> {
>>>>> 	struct zynq_gpio *gpio = platform_get_drvdata(pdev);
>>>>>
>>>>> 	pm_runtime_get_sync(&pdev->dev);
>>>>
>>>> However I don't understand why the get_sync() is here. Maybe Sören can help?
>>>
>>> IIRC, the concern was that the remove function may be called while the device is
>>> runtime suspended. Hence the remove function needs to resume the device since the
>>> remove function may access the HW.
>>
>> What about the corresponding runtime_put()? Would some counter be
>> unbalanced upon device removal?
> 
> Aren't those counters destroyed with module unloading?

I don't know.

Marc

-- 
Pengutronix e.K.                  | Marc Kleine-Budde           |
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