Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
Received-SPF: Pass (protection.outlook.com: domain of amd.com designates
 165.204.84.17 as permitted sender) receiver=protection.outlook.com;
 client-ip=165.204.84.17; helo=SATLEXMB04.amd.com; pr=C
From:   Mario Limonciello <mario.limonciello@amd.com>
To:     <mario.limonciello@amd.com>,
        Mika Westerberg <mika.westerberg@linux.intel.com>,
        Andy Shevchenko <andriy.shevchenko@linux.intel.com>,
        Linus Walleij <linus.walleij@linaro.org>,
        Bartosz Golaszewski <brgl@bgdev.pl>
CC:     Pavel Krc <reg.krn@pkrc.net>, <linux-gpio@vger.kernel.org>,
        <linux-acpi@vger.kernel.org>, <linux-kernel@vger.kernel.org>
Subject: [PATCH 1/2] gpiolib: acpi: Add support to ignore programming an interrupt
Date:   Tue, 19 Jul 2022 09:21:41 -0500
Message-ID: <20220719142142.247-1-mario.limonciello@amd.com>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Content-Type: text/plain
X-MS-Exchange-CrossTenant-OriginalArrivalTime: 19 Jul 2022 14:22:17.3534
 (UTC)
X-MS-Exchange-CrossTenant-Network-Message-Id: cc01b06f-6712-4ee8-a9fc-08da6992158e
X-MS-Exchange-CrossTenant-Id: 3dd8961f-e488-4e60-8e11-a82d994e183d
X-MS-Exchange-CrossTenant-OriginalAttributedTenantConnectingIp: TenantId=3dd8961f-e488-4e60-8e11-a82d994e183d;Ip=[165.204.84.17];Helo=[SATLEXMB04.amd.com]
X-MS-Exchange-CrossTenant-AuthSource: BN8NAM11FT038.eop-nam11.prod.protection.outlook.com
X-MS-Exchange-CrossTenant-AuthAs: Anonymous
X-MS-Exchange-CrossTenant-FromEntityHeader: HybridOnPrem
X-MS-Exchange-Transport-CrossTenantHeadersStamped: CH0PR12MB5346
X-Spam-Status: No, score=-2.1 required=5.0 tests=BAYES_00,DKIM_SIGNED,
        DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,RCVD_IN_DNSWL_NONE,
        RCVD_IN_MSPIKE_H2,SPF_HELO_PASS,SPF_PASS autolearn=ham
        autolearn_force=no version=3.4.6
X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on
        lindbergh.monkeyblade.net
Precedence: bulk
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org

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