From mboxrd@z Thu Jan  1 00:00:00 1970
From: Wanlong Gao <gaowanlong@cn.fujitsu.com>
Subject: Re: [PATCH] input/imx_keypad: add pm suspend and resume functions
Date: Fri, 30 Sep 2011 17:05:44 +0800
Message-ID: <4E858668.2020203@cn.fujitsu.com>
References: <1317369254-31146-1-git-send-email-jason77.wang@gmail.com> <4E857E25.4040503@cn.fujitsu.com> <4E858509.80303@gmail.com>
Reply-To: gaowanlong@cn.fujitsu.com
Mime-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 7bit
Return-path: <linux-input-owner@vger.kernel.org>
Received: from cn.fujitsu.com ([222.73.24.84]:64229 "EHLO song.cn.fujitsu.com"
	rhost-flags-OK-FAIL-OK-OK) by vger.kernel.org with ESMTP
	id S1752895Ab1I3JGu (ORCPT <rfc822;linux-input@vger.kernel.org>);
	Fri, 30 Sep 2011 05:06:50 -0400
In-Reply-To: <4E858509.80303@gmail.com>
Sender: linux-input-owner@vger.kernel.org
List-Id: linux-input@vger.kernel.org
To: Hui Wang <jason77.wang@gmail.com>
Cc: dmitry.torokhov@gmail.com, s.hauer@pengutronix.de, maramaopercheseimorto@gmail.com, linux-input@vger.kernel.org

On 09/30/2011 04:59 PM, Hui Wang wrote:

> Wanlong Gao wrote:
>> On 09/30/2011 03:54 PM, Hui Wang wrote:
>>
>>   
>>> The imx_keypad driver is set wake capable in the imx_keypad_probe(),
>>> but it doesn't implement suspend and reusme callback interface.
>>>
>>> >From the i.MX series MCU Reference Manual, the kpp (keypad port) is
>>> a major wake up source which can detect any key press even in low
>>> power modes and even when there is no clock.
>>>
>>> Now add suspend and resume callback functions for this driver.
>>>
>>> Signed-off-by: Hui Wang <jason77.wang@gmail.com>
>>> ---

>>   
> The i.MX series kpp is not like other normal kpps on other platforms, 
> the kpp on the i.MX can detect key event and wake up system from low 
> power mode even we disable kpp clock. So i choose to unconditionally 
> disable its clock. I have explain it the commit header.
> 
> "From the i.MX series MCU Reference Manual, the kpp (keypad port) is
> 
> a major wake up source which can detect any key press even in low
> power modes and even when there is no clock.
> "
> 


I see.

>>> +
>>> +static int imx_kbd_resume(struct device *dev)
>>> +{
>>> +	struct platform_device *pdev = to_platform_device(dev);
>>> +	struct imx_keypad *kbd = platform_get_drvdata(pdev);
>>> +	struct input_dev *input_dev = kbd->input_dev;
>>> +
>>> +	mutex_lock(&input_dev->mutex);
>>> +
>>> +	if (device_may_wakeup(&pdev->dev))
>>> +		disable_irq_wake(kbd->irq);
>>> +
>>> +	if (input_dev->users)
>>> +		clk_enable(kbd->clk);
>>> +
>>> +	mutex_unlock(&input_dev->mutex);
>>> +
>>> +	return 0;
>>> +}


But is it need to hold a mutex lock also when *disable_irq_wake()* here ?

Thanks
-Wanlong Gao