ACPI: If _TSS exists, do not access FADT.duty_width

Factor out legacy FADT.duty_width code
and run it only in the non _TSS case.

Signed-off-by: Zhao Yakui <yakui.zhao@intel.com>
Signed-off-by: Li Shaohua <shaohua.li@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>

1 files changed, 36 insertions, 30 deletions

diff --git a/drivers/acpi/processor_throttling.c b/drivers/acpi/processor_throttling.c
index 5fa8ac1c0c84..20d82f55ce5f 100644
--- a/drivers/acpi/processor_throttling.c
+++ b/drivers/acpi/processor_throttling.c
@@ -478,6 +478,40 @@ static int acpi_processor_get_throttling(struct acpi_processor *pr)
         return pr->throttling.acpi_processor_get_throttling(pr);
 }
 
+static int acpi_processor_get_fadt_info(struct acpi_processor *pr)
+{
+        int i, step;
+
+        if (!pr->throttling.address) {
+                ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No throttling register\n"));
+                return -EINVAL;
+        } else if (!pr->throttling.duty_width) {
+                ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No throttling states\n"));
+                return -EINVAL;
+        }
+        /* TBD: Support duty_cycle values that span bit 4. */
+        else if ((pr->throttling.duty_offset + pr->throttling.duty_width) > 4) {
+                printk(KERN_WARNING PREFIX "duty_cycle spans bit 4\n");
+                return -EINVAL;
+        }
+
+        pr->throttling.state_count = 1 << acpi_gbl_FADT.duty_width;
+
+        /*
+         * Compute state values. Note that throttling displays a linear power
+         * performance relationship (at 50% performance the CPU will consume
+         * 50% power).  Values are in 1/10th of a percent to preserve accuracy.
+         */
+
+        step = (1000 / pr->throttling.state_count);
+
+        for (i = 0; i < pr->throttling.state_count; i++) {
+                pr->throttling.states[i].performance = 1000 - step * i;
+                pr->throttling.states[i].power = 1000 - step * i;
+        }
+        return 0;
+}
+
 static int acpi_processor_set_throttling_fadt(struct acpi_processor *pr,
                                               int state)
 {
@@ -591,8 +625,6 @@ int acpi_processor_set_throttling(struct acpi_processor *pr, int state)
 int acpi_processor_get_throttling_info(struct acpi_processor *pr)
 {
         int result = 0;
-        int step = 0;
-        int i = 0;
 
         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
                           "pblk_address[0x%08x] duty_offset[%d] duty_width[%d]\n",
@@ -611,6 +643,8 @@ int acpi_processor_get_throttling_info(struct acpi_processor *pr)
                 acpi_processor_get_throttling_states(pr) ||
                 acpi_processor_get_platform_limit(pr))
         {
+                if (acpi_processor_get_fadt_info(pr))
+                        return 0;
                 pr->throttling.acpi_processor_get_throttling =
                     &acpi_processor_get_throttling_fadt;
                 pr->throttling.acpi_processor_set_throttling =
@@ -624,19 +658,6 @@ int acpi_processor_get_throttling_info(struct acpi_processor *pr)
 
         acpi_processor_get_tsd(pr);
 
-        if (!pr->throttling.address) {
-                ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No throttling register\n"));
-                return 0;
-        } else if (!pr->throttling.duty_width) {
-                ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No throttling states\n"));
-                return 0;
-        }
-        /* TBD: Support duty_cycle values that span bit 4. */
-        else if ((pr->throttling.duty_offset + pr->throttling.duty_width) > 4) {
-                printk(KERN_WARNING PREFIX "duty_cycle spans bit 4\n");
-                return 0;
-        }
-
         /*
          * PIIX4 Errata: We don't support throttling on the original PIIX4.
          * This shouldn't be an issue as few (if any) mobile systems ever
@@ -648,21 +669,6 @@ int acpi_processor_get_throttling_info(struct acpi_processor *pr)
                 return 0;
         }
 
-        pr->throttling.state_count = 1 << acpi_gbl_FADT.duty_width;
-
-        /*
-         * Compute state values. Note that throttling displays a linear power/
-         * performance relationship (at 50% performance the CPU will consume
-         * 50% power).  Values are in 1/10th of a percent to preserve accuracy.
-         */
-
-        step = (1000 / pr->throttling.state_count);
-
-        for (i = 0; i < pr->throttling.state_count; i++) {
-                pr->throttling.states[i].performance = step * i;
-                pr->throttling.states[i].power = step * i;
-        }
-
         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found %d throttling states\n",
                           pr->throttling.state_count));