2019-06-18 07:48:58

by Sowjanya Komatineni

[permalink] [raw]
Subject: [PATCH V3 03/17] gpio: tegra: use resume_noirq for tegra gpio resume

During SC7 resume, PARKED bit clear from the pinmux registers may
cause a glitch on the GPIO lines.

So, Tegra GPIOs restore should happen prior to restoring Tegra pinmux
to keep the GPIO lines in a known good state prior to clearing PARKED
bit.

This patch has fix for this by moving Tegra GPIO restore to happen
during resume_noirq.

Signed-off-by: Sowjanya Komatineni <[email protected]>
---
drivers/gpio/gpio-tegra.c | 17 +++++++++++------
1 file changed, 11 insertions(+), 6 deletions(-)

diff --git a/drivers/gpio/gpio-tegra.c b/drivers/gpio/gpio-tegra.c
index f57bfc07ae22..f3c58c597ab9 100644
--- a/drivers/gpio/gpio-tegra.c
+++ b/drivers/gpio/gpio-tegra.c
@@ -410,7 +410,7 @@ static void tegra_gpio_irq_handler(struct irq_desc *desc)
}

#ifdef CONFIG_PM_SLEEP
-static int tegra_gpio_resume(struct device *dev)
+static int tegra_gpio_resume_noirq(struct device *dev)
{
struct tegra_gpio_info *tgi = dev_get_drvdata(dev);
unsigned long flags;
@@ -506,6 +506,15 @@ static int tegra_gpio_irq_set_wake(struct irq_data *d, unsigned int enable)

return irq_set_irq_wake(bank->irq, enable);
}
+
+static const struct dev_pm_ops tegra_gpio_pm_ops = {
+ .suspend = &tegra_gpio_suspend,
+ .resume_noirq = &tegra_gpio_resume_noirq
+};
+
+#define TEGRA_GPIO_PM (&tegra_gpio_pm_ops)
+#else
+#define TEGRA_GPIO_PM NULL
#endif

#ifdef CONFIG_DEBUG_FS
@@ -553,10 +562,6 @@ static inline void tegra_gpio_debuginit(struct tegra_gpio_info *tgi)

#endif

-static const struct dev_pm_ops tegra_gpio_pm_ops = {
- SET_SYSTEM_SLEEP_PM_OPS(tegra_gpio_suspend, tegra_gpio_resume)
-};
-
static int tegra_gpio_probe(struct platform_device *pdev)
{
struct tegra_gpio_info *tgi;
@@ -706,7 +711,7 @@ static const struct of_device_id tegra_gpio_of_match[] = {
static struct platform_driver tegra_gpio_driver = {
.driver = {
.name = "tegra-gpio",
- .pm = &tegra_gpio_pm_ops,
+ .pm = TEGRA_GPIO_PM,
.of_match_table = tegra_gpio_of_match,
},
.probe = tegra_gpio_probe,
--
2.7.4


2019-06-18 11:40:18

by Thierry Reding

[permalink] [raw]
Subject: Re: [PATCH V3 03/17] gpio: tegra: use resume_noirq for tegra gpio resume

On Tue, Jun 18, 2019 at 12:46:17AM -0700, Sowjanya Komatineni wrote:
> During SC7 resume, PARKED bit clear from the pinmux registers may
> cause a glitch on the GPIO lines.
>
> So, Tegra GPIOs restore should happen prior to restoring Tegra pinmux
> to keep the GPIO lines in a known good state prior to clearing PARKED
> bit.
>
> This patch has fix for this by moving Tegra GPIO restore to happen
> during resume_noirq.
>
> Signed-off-by: Sowjanya Komatineni <[email protected]>
> ---
> drivers/gpio/gpio-tegra.c | 17 +++++++++++------
> 1 file changed, 11 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/gpio/gpio-tegra.c b/drivers/gpio/gpio-tegra.c
> index f57bfc07ae22..f3c58c597ab9 100644
> --- a/drivers/gpio/gpio-tegra.c
> +++ b/drivers/gpio/gpio-tegra.c
> @@ -410,7 +410,7 @@ static void tegra_gpio_irq_handler(struct irq_desc *desc)
> }
>
> #ifdef CONFIG_PM_SLEEP
> -static int tegra_gpio_resume(struct device *dev)
> +static int tegra_gpio_resume_noirq(struct device *dev)
> {
> struct tegra_gpio_info *tgi = dev_get_drvdata(dev);
> unsigned long flags;
> @@ -506,6 +506,15 @@ static int tegra_gpio_irq_set_wake(struct irq_data *d, unsigned int enable)
>
> return irq_set_irq_wake(bank->irq, enable);
> }
> +
> +static const struct dev_pm_ops tegra_gpio_pm_ops = {
> + .suspend = &tegra_gpio_suspend,
> + .resume_noirq = &tegra_gpio_resume_noirq
> +};
> +
> +#define TEGRA_GPIO_PM (&tegra_gpio_pm_ops)
> +#else
> +#define TEGRA_GPIO_PM NULL

This seems completely unnecessary...

> #endif
>
> #ifdef CONFIG_DEBUG_FS
> @@ -553,10 +562,6 @@ static inline void tegra_gpio_debuginit(struct tegra_gpio_info *tgi)
>
> #endif
>
> -static const struct dev_pm_ops tegra_gpio_pm_ops = {
> - SET_SYSTEM_SLEEP_PM_OPS(tegra_gpio_suspend, tegra_gpio_resume)
> -};
> -

... because this should work correctly irrespective of how PM_SLEEP is
configured. So I think you just need to:

s/tegra_gpio_resume/tegra_gpio_resume_noirq/

in the above to make this work. No need for this preprocessor macro
business.

Thierry

> static int tegra_gpio_probe(struct platform_device *pdev)
> {
> struct tegra_gpio_info *tgi;
> @@ -706,7 +711,7 @@ static const struct of_device_id tegra_gpio_of_match[] = {
> static struct platform_driver tegra_gpio_driver = {
> .driver = {
> .name = "tegra-gpio",
> - .pm = &tegra_gpio_pm_ops,
> + .pm = TEGRA_GPIO_PM,
> .of_match_table = tegra_gpio_of_match,
> },
> .probe = tegra_gpio_probe,
> --
> 2.7.4
>


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