On Wed, Feb 29, 2012 at 12:15 AM, Kevin Hilman <khilman@xxxxxx> wrote:
> "DebBarma, Tarun Kanti" <tarun.kanti@xxxxxx> writes:
>
>> On Tue, Feb 28, 2012 at 5:24 AM, Kevin Hilman <khilman@xxxxxx> wrote:
>>> Tarun Kanti DebBarma <tarun.kanti@xxxxxx> writes:
>>>
>>>> Since we already have bank->context.wake_en to keep track
>>>> of gpios which are wakeup enabled, there is no need to have
>>>> this field any more.
>>>>
>>>> Signed-off-by: Tarun Kanti DebBarma <tarun.kanti@xxxxxx>
>>>
>>> I'm not crazy about this change...
>>>
>>>> ---
>>>> drivers/gpio/gpio-omap.c | 11 +++++------
>>>> 1 files changed, 5 insertions(+), 6 deletions(-)
>>>>
>>>> diff --git a/drivers/gpio/gpio-omap.c b/drivers/gpio/gpio-omap.c
>>>> index 64f15d5..b62e861 100644
>>>> --- a/drivers/gpio/gpio-omap.c
>>>> +++ b/drivers/gpio/gpio-omap.c
>>>> @@ -53,7 +53,6 @@ struct gpio_bank {
>>>> void __iomem *base;
>>>> u16 irq;
>>>> u16 virtual_irq_start;
>>>> - u32 suspend_wakeup;
>>>> u32 non_wakeup_gpios;
>>>> u32 enabled_non_wakeup_gpios;
>>>> struct gpio_regs context;
>>>> @@ -497,9 +496,9 @@ static int _set_gpio_wakeup(struct gpio_bank *bank, int gpio, int enable)
>>>>
>>>> spin_lock_irqsave(&bank->lock, flags);
>>>> if (enable)
>>>> - bank->suspend_wakeup |= gpio_bit;
>>>> + bank->context.wake_en |= gpio_bit;
>>>> else
>>>> - bank->suspend_wakeup &= ~gpio_bit;
>>>> + bank->context.wake_en &= ~gpio_bit;
>>>
>>> The bank->context values are expected to be copies of the actual
>>> register contents, and here that is clearly not the case.
>> Right, it should have been this:
>>
>> if (enable)
>> - bank->suspend_wakeup |= gpio_bit;
>> + bank->context.wake_en |= gpio_bit;
>> else
>> - bank->suspend_wakeup &= ~gpio_bit;
>> + bank->context.wake_en &= ~gpio_bit;
>> +
>> + __raw_writel(bank->context.wake_en, bank->base + bank->regs->wkup_en);
>>
>>>
>>> With this change, you're using the context register to track changes
>>> that you *might* eventually write to the register.
>> The above change ensures that bank->context.wake_en reflects the
>> latest register value.
>
> OK, but that changes the behavior of the current code.
Agreed.
>
> The current code *only* writes this register in suspend and resume.
> _set_gpio_wakeup() just records the value that is going to be written in
> suspend.
Yes.
>
> Now, I'm not saying we shouldn't make the changes you propose above. We
> probably should be updating the wake-enable register whenever
> _set_gpio_wakeup() is run so that GPIO wakeups work across runtime
> suspend/resume as well.
>
> However, you should probably make that functional change a separate
> patch *before* you do $SUBJECT patch which just changes the variable
> used to cache the register contents.
Sure, I will make this change.
--
Tarun
>
> Kevin
>
>
>> There are two distinct paths through which bank->context.wake_en is
>> updated now, viz:
>> Path1:-
>> chip.irq_set_type() --> gpio_irq_type() --> _set_gpio_triggering() -->
>> set_gpio_trigger()
>>
>> Path2:-
>> chip.irq_set_wake() --> gpio_wake_enable() --> irq_set_wake()
>>
>>>
>>> IMO, this is more confusing than having a separate field to track this.
>> So, there is no need have a separate field to keep track of this.
>> I hope my understanding is right.
>> --
>> Tarun
>>
>>>
>>> Kevin
>>>
>>>> spin_unlock_irqrestore(&bank->lock, flags);
>>>>
>>>> @@ -772,7 +771,7 @@ static int omap_mpuio_suspend_noirq(struct device *dev)
>>>>
>>>> spin_lock_irqsave(&bank->lock, flags);
>>>> bank->context.wake_en = __raw_readl(mask_reg);
>>>> - __raw_writel(0xffff & ~bank->suspend_wakeup, mask_reg);
>>>> + __raw_writel(0xffff & ~bank->context.wake_en, mask_reg);
>>>> spin_unlock_irqrestore(&bank->lock, flags);
>>>>
>>>> return 0;
>>>> @@ -1137,12 +1136,12 @@ static int omap_gpio_suspend(struct device *dev)
>>>> if (!bank->mod_usage || !bank->loses_context)
>>>> return 0;
>>>>
>>>> - if (!bank->regs->wkup_en || !bank->suspend_wakeup)
>>>> + if (!bank->regs->wkup_en || !bank->context.wake_en)
>>>> return 0;
>>>>
>>>> spin_lock_irqsave(&bank->lock, flags);
>>>> _gpio_rmw(base, bank->regs->wkup_en, 0xffffffff, 0);
>>>> - _gpio_rmw(base, bank->regs->wkup_en, bank->suspend_wakeup, 1);
>>>> + _gpio_rmw(base, bank->regs->wkup_en, bank->context.wake_en, 1);
>>>> spin_unlock_irqrestore(&bank->lock, flags);
>>>>
>>>> return 0;
>> --
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