diff --git a/drivers/acpi/acpica/nsprepkg.c b/drivers/acpi/acpica/nsprepkg.c
index 68f7258..1b13b92 100644
--- a/drivers/acpi/acpica/nsprepkg.c
+++ b/drivers/acpi/acpica/nsprepkg.c
@@ -316,6 +316,45 @@
 		    acpi_ns_check_package_list(info, package, elements, count);
 		break;
 
+	case ACPI_PTYPE2_UUID_PAIR:
+
+		/* The package must contain pairs of (UUID + type) */
+
+		if (count & 1) {
+			expected_count = count + 1;
+			goto package_too_small;
+		}
+
+		while (count > 0) {
+			status = acpi_ns_check_object_type(info, elements,
+							   package->ret_info.
+							   object_type1, 0);
+			if (ACPI_FAILURE(status)) {
+				return (status);
+			}
+
+			/* Validate length of the UUID buffer */
+
+			if ((*elements)->buffer.length != 16) {
+				ACPI_WARN_PREDEFINED((AE_INFO,
+						      info->full_pathname,
+						      info->node_flags,
+						      "Invalid length for UUID Buffer"));
+				return (AE_AML_OPERAND_VALUE);
+			}
+
+			status = acpi_ns_check_object_type(info, elements + 1,
+							   package->ret_info.
+							   object_type2, 0);
+			if (ACPI_FAILURE(status)) {
+				return (status);
+			}
+
+			elements += 2;
+			count -= 2;
+		}
+		break;
+
 	default:
 
 		/* Should not get here if predefined info table is correct */
diff --git a/drivers/acpi/ec.c b/drivers/acpi/ec.c
index 9922cc4..cb6066c 100644
--- a/drivers/acpi/ec.c
+++ b/drivers/acpi/ec.c
@@ -1030,6 +1030,10 @@
 	DMI_MATCH(DMI_SYS_VENDOR, "Quanta"),
 	DMI_MATCH(DMI_PRODUCT_NAME, "TW9/SW9"),}, NULL},
 	{
+	ec_flag_msi, "Clevo W350etq", {
+	DMI_MATCH(DMI_SYS_VENDOR, "CLEVO CO."),
+	DMI_MATCH(DMI_PRODUCT_NAME, "W35_37ET"),}, NULL},
+	{
 	ec_validate_ecdt, "ASUS hardware", {
 	DMI_MATCH(DMI_BIOS_VENDOR, "ASUS") }, NULL},
 	{
diff --git a/drivers/acpi/processor_idle.c b/drivers/acpi/processor_idle.c
index 3dca36d..17f9ec5 100644
--- a/drivers/acpi/processor_idle.c
+++ b/drivers/acpi/processor_idle.c
@@ -1071,9 +1071,9 @@
 
 	if (pr->id == 0 && cpuidle_get_driver() == &acpi_idle_driver) {
 
-		cpuidle_pause_and_lock();
 		/* Protect against cpu-hotplug */
 		get_online_cpus();
+		cpuidle_pause_and_lock();
 
 		/* Disable all cpuidle devices */
 		for_each_online_cpu(cpu) {
@@ -1100,8 +1100,8 @@
 				cpuidle_enable_device(dev);
 			}
 		}
-		put_online_cpus();
 		cpuidle_resume_and_unlock();
+		put_online_cpus();
 	}
 
 	return 0;
diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c
index 9a92989..3bf7764 100644
--- a/drivers/acpi/scan.c
+++ b/drivers/acpi/scan.c
@@ -667,8 +667,14 @@
 acpi_device_sun_show(struct device *dev, struct device_attribute *attr,
 		     char *buf) {
 	struct acpi_device *acpi_dev = to_acpi_device(dev);
+	acpi_status status;
+	unsigned long long sun;
 
-	return sprintf(buf, "%lu\n", acpi_dev->pnp.sun);
+	status = acpi_evaluate_integer(acpi_dev->handle, "_SUN", NULL, &sun);
+	if (ACPI_FAILURE(status))
+		return -ENODEV;
+
+	return sprintf(buf, "%llu\n", sun);
 }
 static DEVICE_ATTR(sun, 0444, acpi_device_sun_show, NULL);
 
@@ -690,7 +696,6 @@
 {
 	struct acpi_buffer buffer = {ACPI_ALLOCATE_BUFFER, NULL};
 	acpi_status status;
-	unsigned long long sun;
 	int result = 0;
 
 	/*
@@ -731,14 +736,10 @@
 	if (dev->pnp.unique_id)
 		result = device_create_file(&dev->dev, &dev_attr_uid);
 
-	status = acpi_evaluate_integer(dev->handle, "_SUN", NULL, &sun);
-	if (ACPI_SUCCESS(status)) {
-		dev->pnp.sun = (unsigned long)sun;
+	if (acpi_has_method(dev->handle, "_SUN")) {
 		result = device_create_file(&dev->dev, &dev_attr_sun);
 		if (result)
 			goto end;
-	} else {
-		dev->pnp.sun = (unsigned long)-1;
 	}
 
 	if (acpi_has_method(dev->handle, "_STA")) {
diff --git a/drivers/acpi/video.c b/drivers/acpi/video.c
index 8268843..fcbda10 100644
--- a/drivers/acpi/video.c
+++ b/drivers/acpi/video.c
@@ -82,9 +82,9 @@
  * For Windows 8 systems: used to decide if video module
  * should skip registering backlight interface of its own.
  */
-static int use_native_backlight_param = 1;
+static int use_native_backlight_param = -1;
 module_param_named(use_native_backlight, use_native_backlight_param, int, 0444);
-static bool use_native_backlight_dmi = false;
+static bool use_native_backlight_dmi = true;
 
 static int register_count;
 static struct mutex video_list_lock;
@@ -417,6 +417,12 @@
 	return 0;
 }
 
+static int __init video_disable_native_backlight(const struct dmi_system_id *d)
+{
+	use_native_backlight_dmi = false;
+	return 0;
+}
+
 static struct dmi_system_id video_dmi_table[] __initdata = {
 	/*
 	 * Broken _BQC workaround http://bugzilla.kernel.org/show_bug.cgi?id=13121
@@ -720,6 +726,41 @@
 		DMI_MATCH(DMI_PRODUCT_NAME, "HP EliteBook 8780w"),
 		},
 	},
+
+	/*
+	 * These models have a working acpi_video backlight control, and using
+	 * native backlight causes a regression where backlight does not work
+	 * when userspace is not handling brightness key events. Disable
+	 * native_backlight on these to fix this:
+	 * https://bugzilla.kernel.org/show_bug.cgi?id=81691
+	 */
+	{
+	 .callback = video_disable_native_backlight,
+	 .ident = "ThinkPad T420",
+	 .matches = {
+		DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
+		DMI_MATCH(DMI_PRODUCT_VERSION, "ThinkPad T420"),
+		},
+	},
+	{
+	 .callback = video_disable_native_backlight,
+	 .ident = "ThinkPad T520",
+	 .matches = {
+		DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
+		DMI_MATCH(DMI_PRODUCT_VERSION, "ThinkPad T520"),
+		},
+	},
+
+	/* The native backlight controls do not work on some older machines */
+	{
+	 /* https://bugs.freedesktop.org/show_bug.cgi?id=81515 */
+	 .callback = video_disable_native_backlight,
+	 .ident = "HP ENVY 15 Notebook",
+	 .matches = {
+		DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"),
+		DMI_MATCH(DMI_PRODUCT_NAME, "HP ENVY 15 Notebook PC"),
+		},
+	},
 	{}
 };
 
diff --git a/drivers/cpufreq/intel_pstate.c b/drivers/cpufreq/intel_pstate.c
index e396ad3..0668b38 100644
--- a/drivers/cpufreq/intel_pstate.c
+++ b/drivers/cpufreq/intel_pstate.c
@@ -708,10 +708,6 @@
 
 static int intel_pstate_set_policy(struct cpufreq_policy *policy)
 {
-	struct cpudata *cpu;
-
-	cpu = all_cpu_data[policy->cpu];
-
 	if (!policy->cpuinfo.max_freq)
 		return -ENODEV;
 
diff --git a/include/acpi/acpi_bus.h b/include/acpi/acpi_bus.h
index bcfd808..c1c9de1 100644
--- a/include/acpi/acpi_bus.h
+++ b/include/acpi/acpi_bus.h
@@ -246,7 +246,6 @@
 	acpi_device_name device_name;	/* Driver-determined */
 	acpi_device_class device_class;	/*        "          */
 	union acpi_object *str_obj;	/* unicode string for _STR method */
-	unsigned long sun;		/* _SUN */
 };
 
 #define acpi_device_bid(d)	((d)->pnp.bus_id)
diff --git a/include/linux/pm_domain.h b/include/linux/pm_domain.h
index 7c1d252..ebc4c76 100644
--- a/include/linux/pm_domain.h
+++ b/include/linux/pm_domain.h
@@ -60,7 +60,7 @@
 	struct mutex lock;
 	struct dev_power_governor *gov;
 	struct work_struct power_off_work;
-	char *name;
+	const char *name;
 	unsigned int in_progress;	/* Number of devices being suspended now */
 	atomic_t sd_count;	/* Number of subdomains with power "on" */
 	enum gpd_status status;	/* Current state of the domain */
diff --git a/kernel/power/power.h b/kernel/power/power.h
index 5d49dca..2df883a 100644
--- a/kernel/power/power.h
+++ b/kernel/power/power.h
@@ -179,6 +179,7 @@
 
 #ifdef CONFIG_SUSPEND
 /* kernel/power/suspend.c */
+extern const char *pm_labels[];
 extern const char *pm_states[];
 
 extern int suspend_devices_and_enter(suspend_state_t state);
diff --git a/kernel/power/suspend.c b/kernel/power/suspend.c
index 6dadb25..18c6219 100644
--- a/kernel/power/suspend.c
+++ b/kernel/power/suspend.c
@@ -31,7 +31,7 @@
 
 #include "power.h"
 
-static const char *pm_labels[] = { "mem", "standby", "freeze", };
+const char *pm_labels[] = { "mem", "standby", "freeze", NULL };
 const char *pm_states[PM_SUSPEND_MAX];
 
 static const struct platform_suspend_ops *suspend_ops;
diff --git a/kernel/power/suspend_test.c b/kernel/power/suspend_test.c
index 2f52492..bd91bc1 100644
--- a/kernel/power/suspend_test.c
+++ b/kernel/power/suspend_test.c
@@ -129,20 +129,20 @@
  * at startup time.  They're normally disabled, for faster boot and because
  * we can't know which states really work on this particular system.
  */
-static suspend_state_t test_state __initdata = PM_SUSPEND_ON;
+static const char *test_state_label __initdata;
 
 static char warn_bad_state[] __initdata =
 	KERN_WARNING "PM: can't test '%s' suspend state\n";
 
 static int __init setup_test_suspend(char *value)
 {
-	suspend_state_t i;
+	int i;
 
 	/* "=mem" ==> "mem" */
 	value++;
-	for (i = PM_SUSPEND_MIN; i < PM_SUSPEND_MAX; i++)
-		if (!strcmp(pm_states[i], value)) {
-			test_state = i;
+	for (i = 0; pm_labels[i]; i++)
+		if (!strcmp(pm_labels[i], value)) {
+			test_state_label = pm_labels[i];
 			return 0;
 		}
 
@@ -158,13 +158,21 @@
 
 	struct rtc_device	*rtc = NULL;
 	struct device		*dev;
+	suspend_state_t test_state;
 
 	/* PM is initialized by now; is that state testable? */
-	if (test_state == PM_SUSPEND_ON)
-		goto done;
-	if (!pm_states[test_state]) {
-		printk(warn_bad_state, pm_states[test_state]);
-		goto done;
+	if (!test_state_label)
+		return 0;
+
+	for (test_state = PM_SUSPEND_MIN; test_state < PM_SUSPEND_MAX; test_state++) {
+		const char *state_label = pm_states[test_state];
+
+		if (state_label && !strcmp(test_state_label, state_label))
+			break;
+	}
+	if (test_state == PM_SUSPEND_MAX) {
+		printk(warn_bad_state, test_state_label);
+		return 0;
 	}
 
 	/* RTCs have initialized by now too ... can we use one? */
@@ -173,13 +181,12 @@
 		rtc = rtc_class_open(dev_name(dev));
 	if (!rtc) {
 		printk(warn_no_rtc);
-		goto done;
+		return 0;
 	}
 
 	/* go for it */
 	test_wakealarm(rtc, test_state);
 	rtc_class_close(rtc);
-done:
 	return 0;
 }
 late_initcall(test_suspend);