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Diffstat (limited to 'arch/i386/kernel/cpu/cpufreq/acpi-cpufreq.c')
-rw-r--r--arch/i386/kernel/cpu/cpufreq/acpi-cpufreq.c39
1 files changed, 38 insertions, 1 deletions
diff --git a/arch/i386/kernel/cpu/cpufreq/acpi-cpufreq.c b/arch/i386/kernel/cpu/cpufreq/acpi-cpufreq.c
index e6ea00edcb5..ea19d091fd4 100644
--- a/arch/i386/kernel/cpu/cpufreq/acpi-cpufreq.c
+++ b/arch/i386/kernel/cpu/cpufreq/acpi-cpufreq.c
@@ -32,6 +32,7 @@
#include <linux/seq_file.h>
#include <linux/compiler.h>
#include <linux/sched.h> /* current */
+#include <linux/dmi.h>
#include <asm/io.h>
#include <asm/delay.h>
#include <asm/uaccess.h>
@@ -387,6 +388,33 @@ static int acpi_cpufreq_early_init_acpi(void)
return acpi_processor_preregister_performance(acpi_perf_data);
}
+/*
+ * Some BIOSes do SW_ANY coordination internally, either set it up in hw
+ * or do it in BIOS firmware and won't inform about it to OS. If not
+ * detected, this has a side effect of making CPU run at a different speed
+ * than OS intended it to run at. Detect it and handle it cleanly.
+ */
+static int bios_with_sw_any_bug;
+
+static int __init sw_any_bug_found(struct dmi_system_id *d)
+{
+ bios_with_sw_any_bug = 1;
+ return 0;
+}
+
+static struct dmi_system_id __initdata sw_any_bug_dmi_table[] = {
+ {
+ .callback = sw_any_bug_found,
+ .ident = "Supermicro Server X6DLP",
+ .matches = {
+ DMI_MATCH(DMI_SYS_VENDOR, "Supermicro"),
+ DMI_MATCH(DMI_BIOS_VERSION, "080010"),
+ DMI_MATCH(DMI_PRODUCT_NAME, "X6DLP"),
+ },
+ },
+ { }
+};
+
static int
acpi_cpufreq_cpu_init (
struct cpufreq_policy *policy)
@@ -422,8 +450,17 @@ acpi_cpufreq_cpu_init (
* coordination is required.
*/
if (policy->shared_type == CPUFREQ_SHARED_TYPE_ALL ||
- policy->shared_type == CPUFREQ_SHARED_TYPE_ANY)
+ policy->shared_type == CPUFREQ_SHARED_TYPE_ANY) {
policy->cpus = perf->shared_cpu_map;
+ }
+
+#ifdef CONFIG_SMP
+ dmi_check_system(sw_any_bug_dmi_table);
+ if (bios_with_sw_any_bug && cpus_weight(policy->cpus) == 1) {
+ policy->shared_type = CPUFREQ_SHARED_TYPE_ALL;
+ policy->cpus = cpu_core_map[cpu];
+ }
+#endif
if (cpu_has(c, X86_FEATURE_CONSTANT_TSC)) {
acpi_cpufreq_driver.flags |= CPUFREQ_CONST_LOOPS;