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-rw-r--r--arch/x86/kernel/acpi/boot.c2
-rw-r--r--arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c12
2 files changed, 13 insertions, 1 deletions
diff --git a/arch/x86/kernel/acpi/boot.c b/arch/x86/kernel/acpi/boot.c
index 565e70c7ca9..4f942096291 100644
--- a/arch/x86/kernel/acpi/boot.c
+++ b/arch/x86/kernel/acpi/boot.c
@@ -1548,7 +1548,7 @@ static int __init dmi_ignore_irq0_timer_override(const struct dmi_system_id *d)
/*
* If your system is blacklisted here, but you find that acpi=force
- * works for you, please contact acpi-devel@sourceforge.net
+ * works for you, please contact linux-acpi@vger.kernel.org
*/
static struct dmi_system_id __initdata acpi_dmi_table[] = {
/*
diff --git a/arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c b/arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c
index 4b1c319d30c..89c676d6caf 100644
--- a/arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c
+++ b/arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c
@@ -680,6 +680,18 @@ static int acpi_cpufreq_cpu_init(struct cpufreq_policy *policy)
perf->states[i].transition_latency * 1000;
}
+ /* Check for high latency (>20uS) from buggy BIOSes, like on T42 */
+ if (perf->control_register.space_id == ACPI_ADR_SPACE_FIXED_HARDWARE &&
+ policy->cpuinfo.transition_latency > 20 * 1000) {
+ static int print_once;
+ policy->cpuinfo.transition_latency = 20 * 1000;
+ if (!print_once) {
+ print_once = 1;
+ printk(KERN_INFO "Capping off P-state tranision latency"
+ " at 20 uS\n");
+ }
+ }
+
data->max_freq = perf->states[0].core_frequency * 1000;
/* table init */
for (i=0; i<perf->state_count; i++) {