Re: [PATCH 2/3] gpio: omap: Remove custom PM calls and use cpu_pm instead

[Grygorii Strashko <grygorii.strashko@xxxxxx>]

On 09/20/2018 06:47 PM, Tony Lindgren wrote:
> * Grygorii Strashko <grygorii.strashko@xxxxxx> [180920 23:05]:
>> On 09/20/2018 02:35 PM, Tony Lindgren wrote:
>>> +static int __maybe_unused omap_gpio_runtime_suspend(struct device *dev)
>>> +{
>>> +	struct platform_device *pdev = to_platform_device(dev);
>>> +	struct gpio_bank *bank = platform_get_drvdata(pdev);
>>> +	unsigned long flags;
>>> +	int error = 0;
>>> +
>>> +	raw_spin_lock_irqsave(&bank->lock, flags);
>>> +	/* Must be idled only by CPU_CLUSTER_PM_ENTER? */
>>> +	if (bank->irq_usage) {
>>> +		error = -EBUSY;
>>
>> Sry, I didn't get how will it work with suspend to ram?
>> omap_device will call this handler and, seems, abort suspend always
>> if gpio bank has gpios requested as IRQ. Am I missing smth?
> 
> Heh yeah we have _od_suspend_noirq() call pm_generic_suspend_noirq()
> which will succeed. But note how after that omap_device_idle() gets
> called only if pm_generic_runtime_suspend() == 0 and we still allow
> supend with no error.

Ah, sry, You are right - ret not updated in this case

> 
> So for gpio interrupts there's nothing that needs to be done at that
> point and the cpu_pm notifier will take care of things just before
> suspend.

So, just to summarize:
- gpio requested (incl irq) - is_suspended = true: no actions

- no gpio irqs requested - is_suspended = false: idle->omap_gpio_idle/unidle
  suspend->omap_gpio_runtime_suspend/resume

- gpio irqs requested - is_suspended = false: idle->omap_gpio_idle/unidle
  suspend->omap_gpio_idle/unidle
   

> 
> Do you have any better ideas?

No. It's looks good - thanks, but i'd like to try it, so will get back.


-- 
regards,
-grygorii