6 files changed, 42 insertions, 9 deletions

diff --git a/drivers/acpi/Kconfig b/drivers/acpi/Kconfig
index fe1e8126fbae..fce21c257523 100644
--- a/drivers/acpi/Kconfig
+++ b/drivers/acpi/Kconfig
@@ -197,7 +197,6 @@ config ACPI_ASUS
 config ACPI_IBM
         tristate "IBM ThinkPad Laptop Extras"
         depends on X86
-        default y
         ---help---
           This is a Linux ACPI driver for the IBM ThinkPad laptops. It adds
           support for Fn-Fx key combinations, Bluetooth control, video
diff --git a/drivers/acpi/Makefile b/drivers/acpi/Makefile
index a18243488c66..5984b4f6715a 100644
--- a/drivers/acpi/Makefile
+++ b/drivers/acpi/Makefile
@@ -16,7 +16,7 @@ EXTRA_CFLAGS	+= $(ACPI_CFLAGS)
 # ACPI Boot-Time Table Parsing
 #
 obj-y                           += tables.o
-obj-y                           += blacklist.o
+obj-$(CONFIG_X86)               += blacklist.o
 
 #
 # ACPI Core Subsystem (Interpreter)
diff --git a/drivers/acpi/processor_core.c b/drivers/acpi/processor_core.c
index 421792562642..0c561c571f29 100644
--- a/drivers/acpi/processor_core.c
+++ b/drivers/acpi/processor_core.c
@@ -543,6 +543,8 @@ static int acpi_processor_get_info(struct acpi_processor *pr)
         return_VALUE(0);
 }
 
+static void *processor_device_array[NR_CPUS];
+
 static int acpi_processor_start(struct acpi_device *device)
 {
         int result = 0;
@@ -561,6 +563,19 @@ static int acpi_processor_start(struct acpi_device *device)
 
         BUG_ON((pr->id >= NR_CPUS) || (pr->id < 0));
 
+        /*
+         * Buggy BIOS check
+         * ACPI id of processors can be reported wrongly by the BIOS.
+         * Don't trust it blindly
+         */
+        if (processor_device_array[pr->id] != NULL &&
+            processor_device_array[pr->id] != (void *)device) {
+                ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "BIOS reporting wrong ACPI id"
+                        "for the processor\n"));
+                return_VALUE(-ENODEV);
+        }
+        processor_device_array[pr->id] = (void *)device;
+
         processors[pr->id] = pr;
 
         result = acpi_processor_add_fs(device);
diff --git a/drivers/acpi/processor_idle.c b/drivers/acpi/processor_idle.c
index 70d8a6ec0920..83fd1b6c10c4 100644
--- a/drivers/acpi/processor_idle.c
+++ b/drivers/acpi/processor_idle.c
@@ -280,6 +280,16 @@ static void acpi_processor_idle(void)
 
         cx->usage++;
 
+#ifdef CONFIG_HOTPLUG_CPU
+        /*
+         * Check for P_LVL2_UP flag before entering C2 and above on
+         * an SMP system. We do it here instead of doing it at _CST/P_LVL
+         * detection phase, to work cleanly with logical CPU hotplug.
+         */
+        if ((cx->type != ACPI_STATE_C1) && (num_online_cpus() > 1) && 
+            !pr->flags.has_cst && acpi_fadt.plvl2_up)
+                cx->type = ACPI_STATE_C1;
+#endif
         /*
          * Sleep:
          * ------
@@ -534,6 +544,15 @@ static int acpi_processor_get_power_info_fadt(struct acpi_processor *pr)
         pr->power.states[ACPI_STATE_C0].valid = 1;
         pr->power.states[ACPI_STATE_C1].valid = 1;
 
+#ifndef CONFIG_HOTPLUG_CPU
+        /*
+         * Check for P_LVL2_UP flag before entering C2 and above on
+         * an SMP system. 
+         */
+        if ((num_online_cpus() > 1) && acpi_fadt.plvl2_up)
+                return_VALUE(-ENODEV);
+#endif
+
         /* determine C2 and C3 address from pblk */
         pr->power.states[ACPI_STATE_C2].address = pr->pblk + 4;
         pr->power.states[ACPI_STATE_C3].address = pr->pblk + 5;
@@ -690,7 +709,7 @@ static int acpi_processor_get_power_info_cst(struct acpi_processor *pr)
 
         /* Validate number of power states discovered */
         if (pr->power.count < 2)
-                status = -ENODEV;
+                status = -EFAULT;
 
       end:
         acpi_os_free(buffer.pointer);
@@ -841,11 +860,11 @@ static int acpi_processor_get_power_info(struct acpi_processor *pr)
          * this function */
 
         result = acpi_processor_get_power_info_cst(pr);
-        if ((result) || (acpi_processor_power_verify(pr) < 2)) {
+        if (result == -ENODEV)
                 result = acpi_processor_get_power_info_fadt(pr);
-                if ((result) || (acpi_processor_power_verify(pr) < 2))
-                        result = acpi_processor_get_power_info_default_c1(pr);
-        }
+
+        if ((result) || (acpi_processor_power_verify(pr) < 2))
+                result = acpi_processor_get_power_info_default_c1(pr);
 
         /*
          * Set Default Policy
diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c
index 23e2c6968a11..31218e1d2a18 100644
--- a/drivers/acpi/scan.c
+++ b/drivers/acpi/scan.c
@@ -1110,7 +1110,7 @@ acpi_add_single_object(struct acpi_device **child,
          *
          * TBD: Assumes LDM provides driver hot-plug capability.
          */
-        result = acpi_bus_find_driver(device);
+        acpi_bus_find_driver(device);
 
       end:
         if (!result)
diff --git a/drivers/acpi/video.c b/drivers/acpi/video.c
index f051b151580d..d10668f14699 100644
--- a/drivers/acpi/video.c
+++ b/drivers/acpi/video.c
@@ -812,7 +812,7 @@ acpi_video_device_write_brightness(struct file *file,
 
         ACPI_FUNCTION_TRACE("acpi_video_device_write_brightness");
 
-        if (!dev || count + 1 > sizeof str)
+        if (!dev || !dev->brightness || count + 1 > sizeof str)
                 return_VALUE(-EINVAL);
 
         if (copy_from_user(str, buffer, count))