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Subject: Re: [PATCH 10/14] gpio: omap: Drop the concept of gpio banks not
 being able to lose context.
To:     Tony Lindgren <tony@atomide.com>, Keerthy <j-keerthy@ti.com>
CC:     <linus.walleij@linaro.org>, <t-kristo@ti.com>, <Russ.Dill@ti.com>,
        <linux-omap@vger.kernel.org>, <linux-kernel@vger.kernel.org>,
        <ssantosh@kernel.org>, <haojian.zhuang@linaro.org>,
        <linux-arm-kernel@lists.infradead.org>, <d-gerlach@ti.com>
References: <1523505239-16229-1-git-send-email-j-keerthy@ti.com>
 <1523505239-16229-11-git-send-email-j-keerthy@ti.com>
 <20180412142257.GW5700@atomide.com>
From:   Grygorii Strashko <grygorii.strashko@ti.com>
Message-ID: <3b01e345-6939-f28c-c648-7316d0a410c4@ti.com>
Date:   Thu, 12 Apr 2018 15:10:34 -0500
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On 04/12/2018 09:22 AM, Tony Lindgren wrote:
> * Keerthy <j-keerthy@ti.com> [180412 03:56]:
>> From: Russ Dill <Russ.Dill@ti.com>
>> --- a/drivers/gpio/gpio-omap.c
>> +++ b/drivers/gpio/gpio-omap.c
>> @@ -68,7 +68,7 @@ struct gpio_bank {
>>   	bool dbck_enabled;
>>   	bool is_mpuio;
>>   	bool dbck_flag;
>> -	bool loses_context;
>> +
>>   	bool context_valid;
>>   	int stride;
>>   	u32 width;
> 
> For some SoCs GPIO bank1 won't lose the context ever. So I'd like to
> keep loses_context flag around to avoid pointless save and restore.
> But maybe this still happens with get_context_loss_count and I'm
> misreading this patch?
> 

Agree with Tony here. More over, even if platform supports RTC suspend
(gpio1 context loss) it might support suspend to RAM - gpio1 will not lose context.

Not sure how to handle this correctly now - always-on gpio bank should not be touched 
by omap device framework during suspend otherwise it may hit "in transition" state forever.
From another side it must be handled the same way as other gpio banks in case of RTC suspend.
Q: How to know if current suspend is RTC suspend and not regular suspend to mem?

> However..
> 
>> @@ -1198,15 +1198,9 @@ static int omap_gpio_probe(struct platform_device *pdev)
>>   #ifdef CONFIG_OF_GPIO
>>   	bank->chip.of_node = of_node_get(node);
>>   #endif
>> -	if (node) {
>> -		if (!of_property_read_bool(node, "ti,gpio-always-on"))
>> -			bank->loses_context = true;
>> -	} else {
>> -		bank->loses_context = pdata->loses_context;
>> -
>> -		if (bank->loses_context)
>> -			bank->get_context_loss_count =
>> -				pdata->get_context_loss_count;
>> +	if (!node) {
>> +		bank->get_context_loss_count =
>> +			pdata->get_context_loss_count;
>>   	}
>>   
>>   	if (bank->regs->set_dataout && bank->regs->clr_dataout)
> 
> .. I do have a patch ready here that I'll post after -rc1 to remove
> CONFIG_OMAP_PM_NOOP related stuff, turns out that's noop anyways :)
> 
> So yeah the pdata->get_context_loss_count parts are noop and can
> be just removed.
> 

-- 
regards,
-grygorii