Re: [PATCH] input/imx_keypad: add pm suspend and resume functions

[Hui Wang <jason77.wang@gmail.com>]

Dmitry Torokhov wrote:
> On Fri, Sep 30, 2011 at 04:59:53PM +0800, Hui Wang wrote:
>   
>> Wanlong Gao wrote:
>>     
>>> On 09/30/2011 03:54 PM, Hui Wang wrote:
>>>       
>>>> +
>>>> +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;
>>>> +}
>>>>         
>>> 	struct input_dev *input_dev = kbd->input_dev;
>>> 	if (device_may_wakeup(dev)) {
>>> 		disable_irq_wake(kdb->irq);
>>> 	} else {
>>> 		mutex_lock(&input_dev->mutex);
>>>
>>> 		if (input_dev->users)
>>> 			clk_enable(kbd->clk);
>>>
>>> 		mutex_unlock(&input_dev->mutex);
>>> 	}
>>>
>>>       
>> So, if we unconditionally disable kpp clock in the suspend, we don't
>> need above logic as well in the resume.
>>     
>
> We should not unconditionally disable clock in suspend, you need to check
> if there are any users (or drop check in resume), otherwise you'll get
> unbalanced count in clk (suspend - decrement, resume - not enabling clk
> if device is not being used).
>
> Also locking is needed in suspend.
>
>   
Got it, will fix them in the V2.

Thanks,
Hui.
> Thanks.
>
>