[PATCH 2/2] gpiolib: acpi: Add honor_wakeup module-option + quirk mechanism

[Hans de Goede <hdegoede@redhat.com>]

On some laptops enabling wakeup on the GPIO interrupts used for ACPI _AEI
event handling causes spurious wakeups.

This commit adds a new honor_wakeup option, defaulting to true (our current
behavior), which can be used to disable wakeup on troublesome hardware
to avoid these spurious wakeups.

This is a workaround for an architectural problem with s2idle under Linux
where we do not have any mechanism to immediately go back to sleep after
wakeup events, other then for embedded-controller events using the standard
ACPI EC interface, for details see:
https://lore.kernel.org/linux-acpi/61450f9b-cbc6-0c09-8b3a-aff6bf9a0b3c@redhat.com/

One series of laptops which is not able to suspend without this workaround
is the HP x2 10 Cherry Trail models, this commit adds a DMI based quirk
which makes sets honor_wakeup to false on these models.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
---
 drivers/gpio/gpiolib-acpi.c | 33 ++++++++++++++++++++++++++++++++-
 1 file changed, 32 insertions(+), 1 deletion(-)

diff --git a/drivers/gpio/gpiolib-acpi.c b/drivers/gpio/gpiolib-acpi.c
index 2b47d906d536..9ce9b449ac4b 100644
--- a/drivers/gpio/gpiolib-acpi.c
+++ b/drivers/gpio/gpiolib-acpi.c
@@ -22,12 +22,18 @@
 #include "gpiolib-acpi.h"
 
 #define QUIRK_NO_EDGE_EVENTS_ON_BOOT		0x01l
+#define QUIRK_NO_WAKEUP				0x02l
 
 static int run_edge_events_on_boot = -1;
 module_param(run_edge_events_on_boot, int, 0444);
 MODULE_PARM_DESC(run_edge_events_on_boot,
 		 "Run edge _AEI event-handlers at boot: 0=no, 1=yes, -1=auto");
 
+static int honor_wakeup = -1;
+module_param(honor_wakeup, int, 0444);
+MODULE_PARM_DESC(honor_wakeup,
+		 "Honor the ACPI wake-capable flag: 0=no, 1=yes, -1=auto");
+
 /**
  * struct acpi_gpio_event - ACPI GPIO event handler data
  *
@@ -283,7 +289,8 @@ static acpi_status acpi_gpiochip_alloc_event(struct acpi_resource *ares,
 	event->handle = evt_handle;
 	event->handler = handler;
 	event->irq = irq;
-	event->irq_is_wake = agpio->wake_capable == ACPI_WAKE_CAPABLE;
+	if (honor_wakeup)
+		event->irq_is_wake = agpio->wake_capable == ACPI_WAKE_CAPABLE;
 	event->pin = pin;
 	event->desc = desc;
 
@@ -1337,6 +1344,23 @@ static const struct dmi_system_id gpiolib_acpi_quirks[] = {
 		},
 		.driver_data = (void *)QUIRK_NO_EDGE_EVENTS_ON_BOOT,
 	},
+	{
+		/*
+		 * Various HP X2 10 Cherry Trail models use external
+		 * embedded-controller connected via I2C + a ACPI GPIO
+		 * event handler. The embedded controller generates various
+		 * spurious wakeup events when suspended. So disable wakeup
+		 * for its handler (it used the only ACPI GPIO event handler).
+		 * This breaks wakeup when opening the lid, the user needs
+		 * to press the power-button to wakeup the system. The
+		 * alternative is suspend simply not working, which is worse.
+		 */
+		.matches = {
+			DMI_MATCH(DMI_SYS_VENDOR, "HP"),
+			DMI_MATCH(DMI_PRODUCT_NAME, "HP x2 Detachable 10-p0XX"),
+		},
+		.driver_data = (void *)QUIRK_NO_WAKEUP,
+	},
 	{} /* Terminating entry */
 };
 
@@ -1356,6 +1380,13 @@ static int acpi_gpio_setup_params(void)
 			run_edge_events_on_boot = 1;
 	}
 
+	if (honor_wakeup < 0) {
+		if (quirks & QUIRK_NO_WAKEUP)
+			honor_wakeup = 0;
+		else
+			honor_wakeup = 1;
+	}
+
 	return 0;
 }
 
-- 
2.23.0