[PATCH 1/2] gpiolib: acpi: Add support to ignore programming an interrupt

[Mario Limonciello <mario.limonciello@amd.com>]

gpiolib-acpi already had support for ignoring a pin for wakeup, but
if an OEM configures a floating pin as an interrupt source then
stopping it from being a wakeup won't do much good to stop the
interrupt storm.

Add support for a module parameter and quirk infrastructure to
ignore interrupts as well.

Tested-by: Pavel Krc <reg.krn@pkrc.net>
Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
---
 drivers/gpio/gpiolib-acpi.c | 39 ++++++++++++++++++++++++++++++++-----
 1 file changed, 34 insertions(+), 5 deletions(-)

diff --git a/drivers/gpio/gpiolib-acpi.c b/drivers/gpio/gpiolib-acpi.c
index c2523ac26fac..375942d92d6f 100644
--- a/drivers/gpio/gpiolib-acpi.c
+++ b/drivers/gpio/gpiolib-acpi.c
@@ -32,9 +32,21 @@ MODULE_PARM_DESC(ignore_wake,
 		 "controller@pin combos on which to ignore the ACPI wake flag "
 		 "ignore_wake=controller@pin[,controller@pin[,...]]");
 
+static char *ignore_interrupt;
+module_param(ignore_interrupt, charp, 0444);
+MODULE_PARM_DESC(ignore_interrupt,
+		 "controller@pin combos on which to ignore interrupt "
+		 "ignore_interrupt=controller@pin[,controller@pin[,...]]");
+
 struct acpi_gpiolib_dmi_quirk {
 	bool no_edge_events_on_boot;
 	char *ignore_wake;
+	char *ignore_interrupt;
+};
+
+enum ignore_type {
+	IGNORE_WAKEUP,
+	IGNORE_INTERRUPT,
 };
 
 /**
@@ -317,14 +329,18 @@ static struct gpio_desc *acpi_request_own_gpiod(struct gpio_chip *chip,
 	return desc;
 }
 
-static bool acpi_gpio_in_ignore_list(const char *controller_in, unsigned int pin_in)
+static bool acpi_gpio_in_ignore_list(const char *controller_in, unsigned int pin_in,
+				     enum ignore_type type)
 {
-	const char *controller, *pin_str;
+	const char *controller = NULL, *pin_str;
 	unsigned int pin;
 	char *endp;
 	int len;
 
-	controller = ignore_wake;
+	if (type == IGNORE_WAKEUP)
+		controller = ignore_wake;
+	else if (type == IGNORE_INTERRUPT)
+		controller = ignore_interrupt;
 	while (controller) {
 		pin_str = strchr(controller, '@');
 		if (!pin_str)
@@ -348,7 +364,12 @@ static bool acpi_gpio_in_ignore_list(const char *controller_in, unsigned int pin
 
 	return false;
 err:
-	pr_err_once("Error: Invalid value for gpiolib_acpi.ignore_wake: %s\n", ignore_wake);
+	if (type == IGNORE_WAKEUP)
+		pr_err_once("Error: Invalid value for gpiolib_acpi.ignore_wake: %s\n",
+			    ignore_wake);
+	else if (type == IGNORE_INTERRUPT)
+		pr_err_once("Error: Invalid value for gpiolib_acpi.ignore_interrupt: %s\n",
+			    ignore_interrupt);
 	return false;
 }
 
@@ -360,7 +381,7 @@ static bool acpi_gpio_irq_is_wake(struct device *parent,
 	if (agpio->wake_capable != ACPI_WAKE_CAPABLE)
 		return false;
 
-	if (acpi_gpio_in_ignore_list(dev_name(parent), pin)) {
+	if (acpi_gpio_in_ignore_list(dev_name(parent), pin, IGNORE_WAKEUP)) {
 		dev_info(parent, "Ignoring wakeup on pin %u\n", pin);
 		return false;
 	}
@@ -427,6 +448,11 @@ static acpi_status acpi_gpiochip_alloc_event(struct acpi_resource *ares,
 		goto fail_unlock_irq;
 	}
 
+	if (acpi_gpio_in_ignore_list(dev_name(chip->parent), pin, IGNORE_INTERRUPT)) {
+		dev_info(chip->parent, "Ignoring interrupt on pin %u\n", pin);
+		return AE_OK;
+	}
+
 	event = kzalloc(sizeof(*event), GFP_KERNEL);
 	if (!event)
 		goto fail_unlock_irq;
@@ -1582,6 +1608,9 @@ static int __init acpi_gpio_setup_params(void)
 	if (ignore_wake == NULL && quirk && quirk->ignore_wake)
 		ignore_wake = quirk->ignore_wake;
 
+	if (ignore_interrupt == NULL && quirk && quirk->ignore_interrupt)
+		ignore_interrupt = quirk->ignore_interrupt;
+
 	return 0;
 }
 
-- 
2.34.1