Subject: ACPI : Not use calculated T-states from FADT.duty_width when _TSS exists
>From : Zhao Yakui <yakui.zhao@xxxxxxxxx>
If _TSS exists, it will return supported T-states.
It doesn't make sense to use calculated T-states from FADT.duty_width.
Signed-off-by: Zhao Yakui <yakui.zhao@xxxxxxxxx>
Signed-off-by: Li Shaohua <shaohua.li@xxxxxxxxx>
---
drivers/acpi/processor_throttling.c | 66 +++++++++++++++++++-----------------
1 file changed, 36 insertions(+), 30 deletions(-)
Index: linux-2.6.24-rc1/drivers/acpi/processor_throttling.c
===================================================================
--- linux-2.6.24-rc1.orig/drivers/acpi/processor_throttling.c
+++ linux-2.6.24-rc1/drivers/acpi/processor_throttling.c
@@ -478,6 +478,40 @@ static int acpi_processor_get_throttling
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
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(s
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(s
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(s
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));
-
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