linux-kernel - [PATCH v2 4/8] ACPI: PM: s2idle: Add acpi.sleep_no

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Date:   Tue, 30 Jul 2019 11:59:17 +0200
From:   "Rafael J. Wysocki" <rjw@...ysocki.net>
To:     Linux ACPI <linux-acpi@...r.kernel.org>
Cc:     Linux PM <linux-pm@...r.kernel.org>,
        LKML <linux-kernel@...r.kernel.org>,
        Zhang Rui <rui.zhang@...el.com>,
        Rajneesh Bhardwaj <rajneesh.bhardwaj@...ux.intel.com>,
        Andy Shevchenko <andriy.shevchenko@...ux.intel.com>
Subject: [PATCH v2 4/8] ACPI: PM: s2idle: Add acpi.sleep_no_lps0 module parameter

From: Rafael J. Wysocki <rafael.j.wysocki@...el.com>

Add a module parameter to prevent the ACPI LPS0 _DSM functions
from being invoked (if need be) and rework the suspend-to-idle
blacklist entries in acpisleep_dmi_table[] to make them simply
prevent suspend-to-idle from being used by default on the systems
in question (which really is the original purpose of those entries).

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@...el.com>
---

-> v2: Patch reworked, new subject.

---
 drivers/acpi/sleep.c |   29 ++++++++++++++---------------
 1 file changed, 14 insertions(+), 15 deletions(-)

Index: linux-pm/drivers/acpi/sleep.c
===================================================================
--- linux-pm.orig/drivers/acpi/sleep.c
+++ linux-pm/drivers/acpi/sleep.c
@@ -89,6 +89,10 @@ bool acpi_sleep_state_supported(u8 sleep
 }
 
 #ifdef CONFIG_ACPI_SLEEP
+static bool sleep_no_lps0 __read_mostly;
+module_param(sleep_no_lps0, bool, 0644);
+MODULE_PARM_DESC(sleep_no_lps0, "Do not use the special LPS0 device interface");
+
 static u32 acpi_target_sleep_state = ACPI_STATE_S0;
 
 u32 acpi_target_system_state(void)
@@ -158,11 +162,11 @@ static int __init init_nvs_nosave(const
 	return 0;
 }
 
-static bool acpi_sleep_no_lps0;
+static bool acpi_sleep_default_s3;
 
-static int __init init_no_lps0(const struct dmi_system_id *d)
+static int __init init_default_s3(const struct dmi_system_id *d)
 {
-	acpi_sleep_no_lps0 = true;
+	acpi_sleep_default_s3 = true;
 	return 0;
 }
 
@@ -363,7 +367,7 @@ static const struct dmi_system_id acpisl
 	 * S0 Idle firmware interface.
 	 */
 	{
-	.callback = init_no_lps0,
+	.callback = init_default_s3,
 	.ident = "Dell XPS13 9360",
 	.matches = {
 		DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
@@ -376,7 +380,7 @@ static const struct dmi_system_id acpisl
 	 * https://bugzilla.kernel.org/show_bug.cgi?id=199057).
 	 */
 	{
-	.callback = init_no_lps0,
+	.callback = init_default_s3,
 	.ident = "ThinkPad X1 Tablet(2016)",
 	.matches = {
 		DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
@@ -524,8 +528,9 @@ static void acpi_pm_end(void)
 	acpi_sleep_tts_switch(acpi_target_sleep_state);
 }
 #else /* !CONFIG_ACPI_SLEEP */
+#define sleep_no_lps0	(1)
 #define acpi_target_sleep_state	ACPI_STATE_S0
-#define acpi_sleep_no_lps0	(false)
+#define acpi_sleep_default_s3	(1)
 static inline void acpi_sleep_dmi_check(void) {}
 #endif /* CONFIG_ACPI_SLEEP */
 
@@ -904,12 +909,6 @@ static int lps0_device_attach(struct acp
 	if (lps0_device_handle)
 		return 0;
 
-	if (acpi_sleep_no_lps0) {
-		acpi_handle_info(adev->handle,
-				 "Low Power S0 Idle interface disabled\n");
-		return 0;
-	}
-
 	if (!(acpi_gbl_FADT.flags & ACPI_FADT_LOW_POWER_S0))
 		return 0;
 
@@ -937,7 +936,7 @@ static int lps0_device_attach(struct acp
 	 * Use suspend-to-idle by default if the default suspend mode was not
 	 * set from the command line.
 	 */
-	if (mem_sleep_default > PM_SUSPEND_MEM)
+	if (mem_sleep_default > PM_SUSPEND_MEM && !acpi_sleep_default_s3)
 		mem_sleep_current = PM_SUSPEND_TO_IDLE;
 
 	return 0;
@@ -972,7 +971,7 @@ static int acpi_s2idle_prepare(void)
 
 static int acpi_s2idle_prepare_late(void)
 {
-	if (!lps0_device_handle)
+	if (!lps0_device_handle || sleep_no_lps0)
 		return 0;
 
 	if (pm_debug_messages_on)
@@ -1022,7 +1021,7 @@ static void acpi_s2idle_wake(void)
 
 static void acpi_s2idle_restore_early(void)
 {
-	if (!lps0_device_handle)
+	if (!lps0_device_handle || sleep_no_lps0)
 		return;
 
 	acpi_sleep_run_lps0_dsm(ACPI_LPS0_EXIT);