[PATCH v2] gpio: gpio-omap: Remove conditional pm_runtime handling for GPIO interrupts

[PATCH v2] gpio: gpio-omap: Remove conditional pm_runtime handling for GPIO interrupts

[Tony Lindgren]

From: Russell King <rmk+kernel@armlinux.org.uk>

Commit b764a5863fd8 ("gpio: omap: Remove custom PM calls and use cpu_pm
instead") moved interrupt using GPIO banks to idle with cpu_pm in order
to drop the use of pm_runtime_irq_safe() in a later patch. The GPIO
banks with no interrupts claimed are still being idled based on PM
runtime calls. However this caused a regression for am437x suspend for
rtc+ddr idle mode where the device cannot enter idle state as reported
by Keerthy <j-keerthy@ti.com>.

To fix the issue, we must not fail the pm_runtime callbacks. For GPIO
interrupts, we already have irq_chip_pm_get increment the PM runtime
use count as pointed out by Grygorii Strashko <grygorii.strashko@ti.com>.

So all we need to do is remove the conditional handling in the
runtime_suspend and resume functions and let the CPU PM notifier idle
the GPIO banks.

Cc: Aaro Koskinen <aaro.koskinen@iki.fi>
Cc: Grygorii Strashko <grygorii.strashko@ti.com>
Cc: Keerthy <j-keerthy@ti.com>
Cc: Peter Ujfalusi <peter.ujfalusi@ti.com>
Cc: Tero Kristo <t-kristo@ti.com>
Fixes: b764a5863fd8 ("gpio: omap: Remove custom PM calls and use cpu_pm instead")
Reported-by: Keerthy <j-keerthy@ti.com>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
[tony@atomide.com: updated patch description, dropped runtime count changes]
Signed-off-by: Tony Lindgren <tony@atomide.com>
---

Changes since v1:
- Dropped PM runtime changes to increment count in omap_gpio_irq_startup
  as that's not needed based on comments from Grygorii

- Updated subject and description accordingly

---
 drivers/gpio/gpio-omap.c | 18 ++----------------
 1 file changed, 2 insertions(+), 16 deletions(-)

diff --git a/drivers/gpio/gpio-omap.c b/drivers/gpio/gpio-omap.c
--- a/drivers/gpio/gpio-omap.c
+++ b/drivers/gpio/gpio-omap.c
@@ -1719,40 +1719,26 @@ static int __maybe_unused omap_gpio_runtime_suspend(struct device *dev)
 {
 	struct gpio_bank *bank = dev_get_drvdata(dev);
 	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;
-		goto unlock;
-	}
 	omap_gpio_idle(bank, true);
 	bank->is_suspended = true;
-unlock:
 	raw_spin_unlock_irqrestore(&bank->lock, flags);
 
-	return error;
+	return 0;
 }
 
 static int __maybe_unused omap_gpio_runtime_resume(struct device *dev)
 {
 	struct gpio_bank *bank = dev_get_drvdata(dev);
 	unsigned long flags;
-	int error = 0;
 
 	raw_spin_lock_irqsave(&bank->lock, flags);
-	/* Must be unidled only by CPU_CLUSTER_PM_ENTER? */
-	if (bank->irq_usage) {
-		error = -EBUSY;
-		goto unlock;
-	}
 	omap_gpio_unidle(bank);
 	bank->is_suspended = false;
-unlock:
 	raw_spin_unlock_irqrestore(&bank->lock, flags);
 
-	return error;
+	return 0;
 }
 
 static const struct dev_pm_ops gpio_pm_ops = {
-- 
2.21.0

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Re: [PATCH v2] gpio: gpio-omap: Remove conditional pm_runtime handling for GPIO interrupts

[Keerthy]

On 11/04/19 1:21 AM, Tony Lindgren wrote:
> From: Russell King <rmk+kernel@armlinux.org.uk>
> 
> Commit b764a5863fd8 ("gpio: omap: Remove custom PM calls and use cpu_pm
> instead") moved interrupt using GPIO banks to idle with cpu_pm in order
> to drop the use of pm_runtime_irq_safe() in a later patch. The GPIO
> banks with no interrupts claimed are still being idled based on PM
> runtime calls. However this caused a regression for am437x suspend for
> rtc+ddr idle mode where the device cannot enter idle state as reported
> by Keerthy <j-keerthy@ti.com>.
> 
> To fix the issue, we must not fail the pm_runtime callbacks. For GPIO
> interrupts, we already have irq_chip_pm_get increment the PM runtime
> use count as pointed out by Grygorii Strashko <grygorii.strashko@ti.com>.
> 
> So all we need to do is remove the conditional handling in the
> runtime_suspend and resume functions and let the CPU PM notifier idle
> the GPIO banks.

On am437x-gp-evm Tested for rtc+ddr mode and DS0 back & forth
On am335x-beaglebone-black tested for DS0

Tested-by: Keerthy <j-keerthy@ti.com>
Reviewed-by: Keerthy <j-keerthy@ti.com>

> 
> Cc: Aaro Koskinen <aaro.koskinen@iki.fi>
> Cc: Grygorii Strashko <grygorii.strashko@ti.com>
> Cc: Keerthy <j-keerthy@ti.com>
> Cc: Peter Ujfalusi <peter.ujfalusi@ti.com>
> Cc: Tero Kristo <t-kristo@ti.com>
> Fixes: b764a5863fd8 ("gpio: omap: Remove custom PM calls and use cpu_pm instead")
> Reported-by: Keerthy <j-keerthy@ti.com>
> Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
> [tony@atomide.com: updated patch description, dropped runtime count changes]
> Signed-off-by: Tony Lindgren <tony@atomide.com>
> ---
> 
> Changes since v1:
> - Dropped PM runtime changes to increment count in omap_gpio_irq_startup
>    as that's not needed based on comments from Grygorii
> 
> - Updated subject and description accordingly
> 
> ---
>   drivers/gpio/gpio-omap.c | 18 ++----------------
>   1 file changed, 2 insertions(+), 16 deletions(-)
> 
> diff --git a/drivers/gpio/gpio-omap.c b/drivers/gpio/gpio-omap.c
> --- a/drivers/gpio/gpio-omap.c
> +++ b/drivers/gpio/gpio-omap.c
> @@ -1719,40 +1719,26 @@ static int __maybe_unused omap_gpio_runtime_suspend(struct device *dev)
>   {
>   	struct gpio_bank *bank = dev_get_drvdata(dev);
>   	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;
> -		goto unlock;
> -	}
>   	omap_gpio_idle(bank, true);
>   	bank->is_suspended = true;
> -unlock:
>   	raw_spin_unlock_irqrestore(&bank->lock, flags);
>   
> -	return error;
> +	return 0;
>   }
>   
>   static int __maybe_unused omap_gpio_runtime_resume(struct device *dev)
>   {
>   	struct gpio_bank *bank = dev_get_drvdata(dev);
>   	unsigned long flags;
> -	int error = 0;
>   
>   	raw_spin_lock_irqsave(&bank->lock, flags);
> -	/* Must be unidled only by CPU_CLUSTER_PM_ENTER? */
> -	if (bank->irq_usage) {
> -		error = -EBUSY;
> -		goto unlock;
> -	}
>   	omap_gpio_unidle(bank);
>   	bank->is_suspended = false;
> -unlock:
>   	raw_spin_unlock_irqrestore(&bank->lock, flags);
>   
> -	return error;
> +	return 0;
>   }
>   
>   static const struct dev_pm_ops gpio_pm_ops = {
> 

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Re: [PATCH v2] gpio: gpio-omap: Remove conditional pm_runtime handling for GPIO interrupts

[Linus Walleij]

On Wed, Apr 10, 2019 at 9:51 PM Tony Lindgren <tony@atomide.com> wrote:

> From: Russell King <rmk+kernel@armlinux.org.uk>
>
> Commit b764a5863fd8 ("gpio: omap: Remove custom PM calls and use cpu_pm
> instead") moved interrupt using GPIO banks to idle with cpu_pm in order
> to drop the use of pm_runtime_irq_safe() in a later patch. The GPIO
> banks with no interrupts claimed are still being idled based on PM
> runtime calls. However this caused a regression for am437x suspend for
> rtc+ddr idle mode where the device cannot enter idle state as reported
> by Keerthy <j-keerthy@ti.com>.
>
> To fix the issue, we must not fail the pm_runtime callbacks. For GPIO
> interrupts, we already have irq_chip_pm_get increment the PM runtime
> use count as pointed out by Grygorii Strashko <grygorii.strashko@ti.com>.
>
> So all we need to do is remove the conditional handling in the
> runtime_suspend and resume functions and let the CPU PM notifier idle
> the GPIO banks.
>
> Cc: Aaro Koskinen <aaro.koskinen@iki.fi>
> Cc: Grygorii Strashko <grygorii.strashko@ti.com>
> Cc: Keerthy <j-keerthy@ti.com>
> Cc: Peter Ujfalusi <peter.ujfalusi@ti.com>
> Cc: Tero Kristo <t-kristo@ti.com>
> Fixes: b764a5863fd8 ("gpio: omap: Remove custom PM calls and use cpu_pm instead")
> Reported-by: Keerthy <j-keerthy@ti.com>
> Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
> [tony@atomide.com: updated patch description, dropped runtime count changes]
> Signed-off-by: Tony Lindgren <tony@atomide.com>
> ---
>
> Changes since v1:
> - Dropped PM runtime changes to increment count in omap_gpio_irq_startup
>   as that's not needed based on comments from Grygorii
>
> - Updated subject and description accordingly

Applied this v2 version.

Yours,
Linus Walleij

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