3 files changed, 87 insertions, 30 deletions

diff --git a/drivers/acpi/acpi_pad.c b/drivers/acpi/acpi_pad.c
index 97991ac6f5fc..7e52295f1ecc 100644
--- a/drivers/acpi/acpi_pad.c
+++ b/drivers/acpi/acpi_pad.c
@@ -208,7 +208,7 @@ static int power_saving_thread(void *data)
                  * the mechanism only works when all CPUs have RT task running,
                  * as if one CPU hasn't RT task, RT task from other CPUs will
                  * borrow CPU time from this CPU and cause RT task use > 95%
-                 * CPU time. To make 'avoid staration' work, takes a nap here.
+                 * CPU time. To make 'avoid starvation' work, takes a nap here.
                  */
                 if (do_sleep)
                         schedule_timeout_killable(HZ * idle_pct / 100);
@@ -222,14 +222,18 @@ static struct task_struct *ps_tsks[NR_CPUS];
 static unsigned int ps_tsk_num;
 static int create_power_saving_task(void)
 {
+        int rc = -ENOMEM;
+
         ps_tsks[ps_tsk_num] = kthread_run(power_saving_thread,
                 (void *)(unsigned long)ps_tsk_num,
                 "power_saving/%d", ps_tsk_num);
-        if (ps_tsks[ps_tsk_num]) {
+        rc = IS_ERR(ps_tsks[ps_tsk_num]) ? PTR_ERR(ps_tsks[ps_tsk_num]) : 0;
+        if (!rc)
                 ps_tsk_num++;
-                return 0;
-        }
-        return -EINVAL;
+        else
+                ps_tsks[ps_tsk_num] = NULL;
+
+        return rc;
 }
 
 static void destroy_power_saving_task(void)
@@ -237,6 +241,7 @@ static void destroy_power_saving_task(void)
         if (ps_tsk_num > 0) {
                 ps_tsk_num--;
                 kthread_stop(ps_tsks[ps_tsk_num]);
+                ps_tsks[ps_tsk_num] = NULL;
         }
 }
 
@@ -253,7 +258,7 @@ static void set_power_saving_task_num(unsigned int num)
         }
 }
 
-static int acpi_pad_idle_cpus(unsigned int num_cpus)
+static void acpi_pad_idle_cpus(unsigned int num_cpus)
 {
         get_online_cpus();
 
@@ -261,7 +266,6 @@ static int acpi_pad_idle_cpus(unsigned int num_cpus)
         set_power_saving_task_num(num_cpus);
 
         put_online_cpus();
-        return 0;
 }
 
 static uint32_t acpi_pad_idle_cpus_num(void)
@@ -369,19 +373,21 @@ static void acpi_pad_remove_sysfs(struct acpi_device *device)
 static int acpi_pad_pur(acpi_handle handle, int *num_cpus)
 {
         struct acpi_buffer buffer = {ACPI_ALLOCATE_BUFFER, NULL};
-        acpi_status status;
         union acpi_object *package;
         int rev, num, ret = -EINVAL;
 
-        status = acpi_evaluate_object(handle, "_PUR", NULL, &buffer);
-        if (ACPI_FAILURE(status))
+        if (ACPI_FAILURE(acpi_evaluate_object(handle, "_PUR", NULL, &buffer)))
+                return -EINVAL;
+
+        if (!buffer.length || !buffer.pointer)
                 return -EINVAL;
+
         package = buffer.pointer;
         if (package->type != ACPI_TYPE_PACKAGE || package->package.count != 2)
                 goto out;
         rev = package->package.elements[0].integer.value;
         num = package->package.elements[1].integer.value;
-        if (rev != 1)
+        if (rev != 1 || num < 0)
                 goto out;
         *num_cpus = num;
         ret = 0;
@@ -410,7 +416,7 @@ static void acpi_pad_ost(acpi_handle handle, int stat,
 
 static void acpi_pad_handle_notify(acpi_handle handle)
 {
-        int num_cpus, ret;
+        int num_cpus;
         uint32_t idle_cpus;
 
         mutex_lock(&isolated_cpus_lock);
@@ -418,12 +424,9 @@ static void acpi_pad_handle_notify(acpi_handle handle)
                 mutex_unlock(&isolated_cpus_lock);
                 return;
         }
-        ret = acpi_pad_idle_cpus(num_cpus);
+        acpi_pad_idle_cpus(num_cpus);
         idle_cpus = acpi_pad_idle_cpus_num();
-        if (!ret)
-                acpi_pad_ost(handle, 0, idle_cpus);
-        else
-                acpi_pad_ost(handle, 1, 0);
+        acpi_pad_ost(handle, 0, idle_cpus);
         mutex_unlock(&isolated_cpus_lock);
 }
 
diff --git a/drivers/acpi/sleep.c b/drivers/acpi/sleep.c
index 5f2c379ab7bf..79d33d908b5a 100644
--- a/drivers/acpi/sleep.c
+++ b/drivers/acpi/sleep.c
@@ -81,6 +81,23 @@ static int acpi_sleep_prepare(u32 acpi_state)
 #ifdef CONFIG_ACPI_SLEEP
 static u32 acpi_target_sleep_state = ACPI_STATE_S0;
 /*
+ * According to the ACPI specification the BIOS should make sure that ACPI is
+ * enabled and SCI_EN bit is set on wake-up from S1 - S3 sleep states.  Still,
+ * some BIOSes don't do that and therefore we use acpi_enable() to enable ACPI
+ * on such systems during resume.  Unfortunately that doesn't help in
+ * particularly pathological cases in which SCI_EN has to be set directly on
+ * resume, although the specification states very clearly that this flag is
+ * owned by the hardware.  The set_sci_en_on_resume variable will be set in such
+ * cases.
+ */
+static bool set_sci_en_on_resume;
+
+void __init acpi_set_sci_en_on_resume(void)
+{
+        set_sci_en_on_resume = true;
+}
+
+/*
  * ACPI 1.0 wants us to execute _PTS before suspending devices, so we allow the
  * user to request that behavior by using the 'acpi_old_suspend_ordering'
  * kernel command line option that causes the following variable to be set.
@@ -170,18 +187,6 @@ static void acpi_pm_end(void)
 #endif /* CONFIG_ACPI_SLEEP */
 
 #ifdef CONFIG_SUSPEND
-/*
- * According to the ACPI specification the BIOS should make sure that ACPI is
- * enabled and SCI_EN bit is set on wake-up from S1 - S3 sleep states.  Still,
- * some BIOSes don't do that and therefore we use acpi_enable() to enable ACPI
- * on such systems during resume.  Unfortunately that doesn't help in
- * particularly pathological cases in which SCI_EN has to be set directly on
- * resume, although the specification states very clearly that this flag is
- * owned by the hardware.  The set_sci_en_on_resume variable will be set in such
- * cases.
- */
-static bool set_sci_en_on_resume;
-
 extern void do_suspend_lowlevel(void);
 
 static u32 acpi_suspend_states[] = {
diff --git a/drivers/acpi/video.c b/drivers/acpi/video.c
index 05dff631591c..b765790b32be 100644
--- a/drivers/acpi/video.c
+++ b/drivers/acpi/video.c
@@ -78,6 +78,13 @@ MODULE_LICENSE("GPL");
 static int brightness_switch_enabled = 1;
 module_param(brightness_switch_enabled, bool, 0644);
 
+/*
+ * By default, we don't allow duplicate ACPI video bus devices
+ * under the same VGA controller
+ */
+static int allow_duplicates;
+module_param(allow_duplicates, bool, 0644);
+
 static int register_count = 0;
 static int acpi_video_bus_add(struct acpi_device *device);
 static int acpi_video_bus_remove(struct acpi_device *device, int type);
@@ -999,8 +1006,10 @@ static void acpi_video_device_find_cap(struct acpi_video_device *device)
                 sprintf(name, "acpi_video%d", count++);
                 device->backlight = backlight_device_register(name,
                         NULL, device, &acpi_backlight_ops);
-                device->backlight->props.max_brightness = device->brightness->count-3;
                 kfree(name);
+                if (IS_ERR(device->backlight))
+                        return;
+                device->backlight->props.max_brightness = device->brightness->count-3;
 
                 result = sysfs_create_link(&device->backlight->dev.kobj,
                                            &device->dev->dev.kobj, "device");
@@ -1979,6 +1988,10 @@ acpi_video_switch_brightness(struct acpi_video_device *device, int event)
         unsigned long long level_current, level_next;
         int result = -EINVAL;
 
+        /* no warning message if acpi_backlight=vendor is used */
+        if (!acpi_video_backlight_support())
+                return 0;
+
         if (!device->brightness)
                 goto out;
 
@@ -2233,11 +2246,47 @@ static int acpi_video_resume(struct acpi_device *device)
         return AE_OK;
 }
 
+static acpi_status
+acpi_video_bus_match(acpi_handle handle, u32 level, void *context,
+                        void **return_value)
+{
+        struct acpi_device *device = context;
+        struct acpi_device *sibling;
+        int result;
+
+        if (handle == device->handle)
+                return AE_CTRL_TERMINATE;
+
+        result = acpi_bus_get_device(handle, &sibling);
+        if (result)
+                return AE_OK;
+
+        if (!strcmp(acpi_device_name(sibling), ACPI_VIDEO_BUS_NAME))
+                        return AE_ALREADY_EXISTS;
+
+        return AE_OK;
+}
+
 static int acpi_video_bus_add(struct acpi_device *device)
 {
         struct acpi_video_bus *video;
         struct input_dev *input;
         int error;
+        acpi_status status;
+
+        status = acpi_walk_namespace(ACPI_TYPE_DEVICE,
+                                device->parent->handle, 1,
+                                acpi_video_bus_match, NULL,
+                                device, NULL);
+        if (status == AE_ALREADY_EXISTS) {
+                printk(KERN_WARNING FW_BUG
+                        "Duplicate ACPI video bus devices for the"
+                        " same VGA controller, please try module "
+                        "parameter \"video.allow_duplicates=1\""
+                        "if the current driver doesn't work.\n");
+                if (!allow_duplicates)
+                        return -ENODEV;
+        }
 
         video = kzalloc(sizeof(struct acpi_video_bus), GFP_KERNEL);
         if (!video)