Commit aad41832 authored by Asmaa Mnebhi's avatar Asmaa Mnebhi Committed by Bartosz Golaszewski
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gpio: mlxbf3: Support shutdown() function 



During Linux graceful reboot, the GPIO interrupts are not disabled.
Since the drivers are not removed during graceful reboot,
the logic to call mlxbf3_gpio_irq_disable() is not triggered.
Interrupts that remain enabled can cause issues on subsequent boots.

For example, the mlxbf-gige driver contains PHY logic to bring up the link.
If the gpio-mlxbf3 driver loads first, the mlxbf-gige driver
will use a GPIO interrupt to bring up the link.
Otherwise, it will use polling.
The next time Linux boots and loads the drivers in this order, we encounter the issue:
- mlxbf-gige loads first and uses polling while the GPIO10
  interrupt is still enabled from the previous boot. So if
  the interrupt triggers, there is nothing to clear it.
- gpio-mlxbf3 loads.
- i2c-mlxbf loads. The interrupt doesn't trigger for I2C
  because it is shared with the GPIO interrupt line which
  was not cleared.

The solution is to add a shutdown function to the GPIO driver to clear and disable
all interrupts. Also clear the interrupt after disabling it in mlxbf3_gpio_irq_disable().

Fixes: 38a700ef ("gpio: mlxbf3: Add gpio driver support")
Signed-off-by: default avatarAsmaa Mnebhi <asmaa@nvidia.com>
Reviewed-by: default avatarDavid Thompson <davthompson@nvidia.com>
Reviewed-by: default avatarAndy Shevchenko <andy@kernel.org>
Reviewed-by: default avatarLinus Walleij <linus.walleij@linaro.org>
Link: https://lore.kernel.org/r/20240611171509.22151-1-asmaa@nvidia.com


Signed-off-by: default avatarBartosz Golaszewski <bartosz.golaszewski@linaro.org>
parent 8400291e

drivers/gpio/gpio-mlxbf3.c

+14 −0
Original line number Diff line number Diff line
@@ -39,6 +39,8 @@ 
#define MLXBF_GPIO_CAUSE_OR_EVTEN0        0x14

#define MLXBF_GPIO_CAUSE_OR_CLRCAUSE      0x18



#define MLXBF_GPIO_CLR_ALL_INTS           GENMASK(31, 0)



struct mlxbf3_gpio_context {

	struct gpio_chip gc;
@@ -82,6 +84,8 @@ static void mlxbf3_gpio_irq_disable(struct irq_data *irqd) 
	val = readl(gs->gpio_cause_io + MLXBF_GPIO_CAUSE_OR_EVTEN0);

	val &= ~BIT(offset);

	writel(val, gs->gpio_cause_io + MLXBF_GPIO_CAUSE_OR_EVTEN0);



	writel(BIT(offset), gs->gpio_cause_io + MLXBF_GPIO_CAUSE_OR_CLRCAUSE);

	raw_spin_unlock_irqrestore(&gs->gc.bgpio_lock, flags);



	gpiochip_disable_irq(gc, offset);
@@ -253,6 +257,15 @@ static int mlxbf3_gpio_probe(struct platform_device *pdev) 
	return 0;

}



static void mlxbf3_gpio_shutdown(struct platform_device *pdev)

{

	struct mlxbf3_gpio_context *gs = platform_get_drvdata(pdev);



	/* Disable and clear all interrupts */

	writel(0, gs->gpio_cause_io + MLXBF_GPIO_CAUSE_OR_EVTEN0);

	writel(MLXBF_GPIO_CLR_ALL_INTS, gs->gpio_cause_io + MLXBF_GPIO_CAUSE_OR_CLRCAUSE);

}



static const struct acpi_device_id mlxbf3_gpio_acpi_match[] = {

	{ "MLNXBF33", 0 },

	{}
@@ -265,6 +278,7 @@ static struct platform_driver mlxbf3_gpio_driver = { 
		.acpi_match_table = mlxbf3_gpio_acpi_match,

	},

	.probe    = mlxbf3_gpio_probe,

	.shutdown = mlxbf3_gpio_shutdown,

};

module_platform_driver(mlxbf3_gpio_driver);