ACPI: PM: Set up EC GPE for system wakeup from drivers that need it

The EC GPE needs to be set up for system wakeup only if there is a
driver depending on it, either intel-hid or intel-vbtn, bound to a
button device that is expected to wake up the system from sleep (such
as the power button on some Dell systems, like the XPS13 9360).  It
doesn't need to be set up for waking up the system from sleep in any
other cases and whether or not it is expected to wake up the system
from sleep doesn't depend on whether or not the LPS0 device is
present in the ACPI namespace.

For this reason, rearrange the ACPI suspend-to-idle code to make the
drivers depending on the EC GPE wakeup take care of setting it up and
decouple that from the LPS0 device handling.

While at it, make intel-hid and intel-vbtn prepare for system wakeup
only if they are allowed to wake up the system from sleep by user
space (via sysfs).

[Note that acpi_ec_mark_gpe_for_wake() and acpi_ec_set_gpe_wake_mask()
 are there to prevent the EC GPE from being disabled by the
 acpi_enable_all_wakeup_gpes() call in acpi_s2idle_prepare(), so on
 systems with either intel-hid or intel-vbtn this change doesn't
 affect any interactions with the hardware or platform firmware.]

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>

drivers/acpi/ec.c

@@ -25,6 +25,7 @@
 #include <linux/list.h>
 #include <linux/spinlock.h>
 #include <linux/slab.h>
+#include <linux/suspend.h>
 #include <linux/acpi.h>
 #include <linux/dmi.h>
 #include <asm/io.h>
@@ -1048,17 +1049,21 @@ void acpi_ec_unblock_transactions(void)
 		acpi_ec_start(first_ec, true);
 }
 
+#ifdef CONFIG_PM_SLEEP
 void acpi_ec_mark_gpe_for_wake(void)
 {
 	if (first_ec && !ec_no_wakeup)
 		acpi_mark_gpe_for_wake(NULL, first_ec->gpe);
 }
+EXPORT_SYMBOL_GPL(acpi_ec_mark_gpe_for_wake);
 
 void acpi_ec_set_gpe_wake_mask(u8 action)
 {
-	if (first_ec && !ec_no_wakeup)
+	if (pm_suspend_no_platform() && first_ec && !ec_no_wakeup)
 		acpi_set_gpe_wake_mask(NULL, first_ec->gpe, action);
 }
+EXPORT_SYMBOL_GPL(acpi_ec_set_gpe_wake_mask);
+#endif
 
 bool acpi_ec_dispatch_gpe(void)
 {

drivers/acpi/internal.h

@@ -194,8 +194,6 @@ void acpi_ec_ecdt_probe(void);
 void acpi_ec_dsdt_probe(void);
 void acpi_ec_block_transactions(void);
 void acpi_ec_unblock_transactions(void);
-void acpi_ec_mark_gpe_for_wake(void);
-void acpi_ec_set_gpe_wake_mask(u8 action);
 bool acpi_ec_dispatch_gpe(void);
 int acpi_ec_add_query_handler(struct acpi_ec *ec, u8 query_bit,
 			      acpi_handle handle, acpi_ec_query_func func,

drivers/acpi/sleep.c

@@ -930,8 +930,6 @@ static int lps0_device_attach(struct acpi_device *adev,
 
 		acpi_handle_debug(adev->handle, "_DSM function mask: 0x%x\n",
 				  bitmask);
-
-		acpi_ec_mark_gpe_for_wake();
 	} else {
 		acpi_handle_debug(adev->handle,
 				  "_DSM function 0 evaluation failed\n");
@@ -960,8 +958,6 @@ static int acpi_s2idle_prepare(void)
 	if (lps0_device_handle) {
 		acpi_sleep_run_lps0_dsm(ACPI_LPS0_SCREEN_OFF);
 		acpi_sleep_run_lps0_dsm(ACPI_LPS0_ENTRY);
-
-		acpi_ec_set_gpe_wake_mask(ACPI_GPE_ENABLE);
 	}
 
 	if (acpi_sci_irq_valid())
@@ -979,10 +975,7 @@ static int acpi_s2idle_prepare(void)
 
 static void acpi_s2idle_wake(void)
 {
-	if (!lps0_device_handle)
-		return;
-
-	if (pm_debug_messages_on)
+	if (lps0_device_handle && pm_debug_messages_on)
 		lpi_check_constraints();
 
 	/*
@@ -1031,8 +1024,6 @@ static void acpi_s2idle_restore(void)
 		disable_irq_wake(acpi_sci_irq);
 
 	if (lps0_device_handle) {
-		acpi_ec_set_gpe_wake_mask(ACPI_GPE_DISABLE);
-
 		acpi_sleep_run_lps0_dsm(ACPI_LPS0_EXIT);
 		acpi_sleep_run_lps0_dsm(ACPI_LPS0_SCREEN_ON);
 	}
@@ -1081,7 +1072,7 @@ bool acpi_s2idle_wakeup(void)
 
 bool acpi_sleep_no_ec_events(void)
 {
-	return !s2idle_in_progress || !lps0_device_handle;
+	return !s2idle_in_progress;
 }
 
 #ifdef CONFIG_PM_SLEEP

drivers/platform/x86/intel-hid.c

@@ -253,9 +253,12 @@ static void intel_button_array_enable(struct device *device, bool enable)
 
 static int intel_hid_pm_prepare(struct device *device)
 {
-	struct intel_hid_priv *priv = dev_get_drvdata(device);
+	if (device_may_wakeup(device)) {
+		struct intel_hid_priv *priv = dev_get_drvdata(device);
 
-	priv->wakeup_mode = true;
+		priv->wakeup_mode = true;
+		acpi_ec_set_gpe_wake_mask(ACPI_GPE_ENABLE);
+	}
 	return 0;
 }
 
@@ -270,9 +273,12 @@ static int intel_hid_pl_suspend_handler(struct device *device)
 
 static int intel_hid_pl_resume_handler(struct device *device)
 {
-	struct intel_hid_priv *priv = dev_get_drvdata(device);
+	if (device_may_wakeup(device)) {
+		struct intel_hid_priv *priv = dev_get_drvdata(device);
 
-	priv->wakeup_mode = false;
+		acpi_ec_set_gpe_wake_mask(ACPI_GPE_DISABLE);
+		priv->wakeup_mode = false;
+	}
 	if (pm_resume_via_firmware()) {
 		intel_hid_set_enable(device, true);
 		intel_button_array_enable(device, true);
@@ -491,6 +497,12 @@ static int intel_hid_probe(struct platform_device *device)
 	}
 
 	device_init_wakeup(&device->dev, true);
+	/*
+	 * In order for system wakeup to work, the EC GPE has to be marked as
+	 * a wakeup one, so do that here (this setting will persist, but it has
+	 * no effect until the wakeup mask is set for the EC GPE).
+	 */
+	acpi_ec_mark_gpe_for_wake();
 	return 0;
 
 err_remove_notify:

drivers/platform/x86/intel-vbtn.c

@@ -176,6 +176,12 @@ static int intel_vbtn_probe(struct platform_device *device)
 		return -EBUSY;
 
 	device_init_wakeup(&device->dev, true);
+	/*
+	 * In order for system wakeup to work, the EC GPE has to be marked as
+	 * a wakeup one, so do that here (this setting will persist, but it has
+	 * no effect until the wakeup mask is set for the EC GPE).
+	 */
+	acpi_ec_mark_gpe_for_wake();
 	return 0;
 }
 
@@ -195,17 +201,23 @@ static int intel_vbtn_remove(struct platform_device *device)
 
 static int intel_vbtn_pm_prepare(struct device *dev)
 {
-	struct intel_vbtn_priv *priv = dev_get_drvdata(dev);
+	if (device_may_wakeup(dev)) {
+		struct intel_vbtn_priv *priv = dev_get_drvdata(dev);
 
-	priv->wakeup_mode = true;
+		priv->wakeup_mode = true;
+		acpi_ec_set_gpe_wake_mask(ACPI_GPE_ENABLE);
+	}
 	return 0;
 }
 
 static int intel_vbtn_pm_resume(struct device *dev)
 {
-	struct intel_vbtn_priv *priv = dev_get_drvdata(dev);
+	if (device_may_wakeup(dev)) {
+		struct intel_vbtn_priv *priv = dev_get_drvdata(dev);
 
-	priv->wakeup_mode = false;
+		acpi_ec_set_gpe_wake_mask(ACPI_GPE_DISABLE);
+		priv->wakeup_mode = false;
+	}
 	return 0;
 }
 

include/linux/acpi.h

@@ -931,6 +931,8 @@ int acpi_subsys_suspend_noirq(struct device *dev);
 int acpi_subsys_suspend(struct device *dev);
 int acpi_subsys_freeze(struct device *dev);
 int acpi_subsys_poweroff(struct device *dev);
+void acpi_ec_mark_gpe_for_wake(void);
+void acpi_ec_set_gpe_wake_mask(u8 action);
 #else
 static inline int acpi_subsys_prepare(struct device *dev) { return 0; }
 static inline void acpi_subsys_complete(struct device *dev) {}
@@ -939,6 +941,8 @@ static inline int acpi_subsys_suspend_noirq(struct device *dev) { return 0; }
 static inline int acpi_subsys_suspend(struct device *dev) { return 0; }
 static inline int acpi_subsys_freeze(struct device *dev) { return 0; }
 static inline int acpi_subsys_poweroff(struct device *dev) { return 0; }
+static inline void acpi_ec_mark_gpe_for_wake(void) {}
+static inline void acpi_ec_set_gpe_wake_mask(u8 action) {}
 #endif
 
 #ifdef CONFIG_ACPI

include/linux/suspend.h

@@ -335,6 +335,7 @@ static inline void pm_set_suspend_via_firmware(void) {}
 static inline void pm_set_resume_via_firmware(void) {}
 static inline bool pm_suspend_via_firmware(void) { return false; }
 static inline bool pm_resume_via_firmware(void) { return false; }
+static inline bool pm_suspend_no_platform(void) { return false; }
 static inline bool pm_suspend_default_s2idle(void) { return false; }
 
 static inline void suspend_set_ops(const struct platform_suspend_ops *ops) {}