From: Mario Limonciello <mario.limonciello@amd.com>
Date: Mon, 29 Aug 2022 16:29:49 +0000 (-0500)
Subject: ACPI: s2idle: Add a new ->check() callback for platform_s2idle_ops
X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=811d59fdf56a17c66742578fe8be8a6a841af448;p=linux.git

ACPI: s2idle: Add a new ->check() callback for platform_s2idle_ops

On some platforms it is found that Linux more aggressively enters s2idle
than Windows enters Modern Standby and this uncovers some synchronization
issues for the platform.  To aid in debugging this class of problems in
the future, add support for an extra optional callback intended for
drivers to emit extra debugging.

Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Link: https://lore.kernel.org/r/20220829162953.5947-2-mario.limonciello@amd.com
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
---

diff --git a/drivers/acpi/sleep.h b/drivers/acpi/sleep.h
index 7fe41ee489d61..d960a238be4e5 100644
--- a/drivers/acpi/sleep.h
+++ b/drivers/acpi/sleep.h
@@ -18,6 +18,7 @@ static inline acpi_status acpi_set_waking_vector(u32 wakeup_address)
 extern int acpi_s2idle_begin(void);
 extern int acpi_s2idle_prepare(void);
 extern int acpi_s2idle_prepare_late(void);
+extern void acpi_s2idle_check(void);
 extern bool acpi_s2idle_wake(void);
 extern void acpi_s2idle_restore_early(void);
 extern void acpi_s2idle_restore(void);
diff --git a/drivers/acpi/x86/s2idle.c b/drivers/acpi/x86/s2idle.c
index f9ac12b778e6a..474aa46f82f60 100644
--- a/drivers/acpi/x86/s2idle.c
+++ b/drivers/acpi/x86/s2idle.c
@@ -486,6 +486,19 @@ int acpi_s2idle_prepare_late(void)
 	return 0;
 }
 
+void acpi_s2idle_check(void)
+{
+	struct acpi_s2idle_dev_ops *handler;
+
+	if (!lps0_device_handle || sleep_no_lps0)
+		return;
+
+	list_for_each_entry(handler, &lps0_s2idle_devops_head, list_node) {
+		if (handler->check)
+			handler->check();
+	}
+}
+
 void acpi_s2idle_restore_early(void)
 {
 	struct acpi_s2idle_dev_ops *handler;
@@ -527,6 +540,7 @@ static const struct platform_s2idle_ops acpi_s2idle_ops_lps0 = {
 	.begin = acpi_s2idle_begin,
 	.prepare = acpi_s2idle_prepare,
 	.prepare_late = acpi_s2idle_prepare_late,
+	.check = acpi_s2idle_check,
 	.wake = acpi_s2idle_wake,
 	.restore_early = acpi_s2idle_restore_early,
 	.restore = acpi_s2idle_restore,
diff --git a/include/linux/acpi.h b/include/linux/acpi.h
index 6f64b2f3dc547..acaa2ddc067d3 100644
--- a/include/linux/acpi.h
+++ b/include/linux/acpi.h
@@ -1075,6 +1075,7 @@ acpi_status acpi_os_prepare_extended_sleep(u8 sleep_state,
 struct acpi_s2idle_dev_ops {
 	struct list_head list_node;
 	void (*prepare)(void);
+	void (*check)(void);
 	void (*restore)(void);
 };
 int acpi_register_lps0_dev(struct acpi_s2idle_dev_ops *arg);
diff --git a/include/linux/suspend.h b/include/linux/suspend.h
index 70f2921e2e703..03ed42ed2c7f6 100644
--- a/include/linux/suspend.h
+++ b/include/linux/suspend.h
@@ -191,6 +191,7 @@ struct platform_s2idle_ops {
 	int (*begin)(void);
 	int (*prepare)(void);
 	int (*prepare_late)(void);
+	void (*check)(void);
 	bool (*wake)(void);
 	void (*restore_early)(void);
 	void (*restore)(void);
diff --git a/kernel/power/suspend.c b/kernel/power/suspend.c
index 827075944d283..c6272d466e58e 100644
--- a/kernel/power/suspend.c
+++ b/kernel/power/suspend.c
@@ -136,6 +136,9 @@ static void s2idle_loop(void)
 			break;
 		}
 
+		if (s2idle_ops && s2idle_ops->check)
+			s2idle_ops->check();
+
 		s2idle_enter();
 	}