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-rw-r--r--drivers/cpufreq/e_powersaver.c18
1 files changed, 18 insertions, 0 deletions
diff --git a/drivers/cpufreq/e_powersaver.c b/drivers/cpufreq/e_powersaver.c
index 2882d40a3084..4bd6815d317b 100644
--- a/drivers/cpufreq/e_powersaver.c
+++ b/drivers/cpufreq/e_powersaver.c
@@ -43,6 +43,7 @@ static struct eps_cpu_data *eps_cpu[NR_CPUS];
/* Module parameters */
static int freq_failsafe_off;
static int voltage_failsafe_off;
+static int set_max_voltage;
#if defined CONFIG_ACPI_PROCESSOR || defined CONFIG_ACPI_PROCESSOR_MODULE
static int ignore_acpi_limit;
@@ -340,6 +341,21 @@ static int eps_cpu_init(struct cpufreq_policy *policy)
}
#endif
+ /* Allow user to set lower maximum voltage then that reported
+ * by processor */
+ if (brand == EPS_BRAND_C7M && set_max_voltage) {
+ u32 v;
+
+ /* Change mV to something hardware can use */
+ v = (set_max_voltage - 700) / 16;
+ /* Check if voltage is within limits */
+ if (v >= min_voltage && v <= max_voltage) {
+ printk(KERN_INFO "eps: Setting %dmV as maximum.\n",
+ v * 16 + 700);
+ max_voltage = v;
+ }
+ }
+
/* Calc number of p-states supported */
if (brand == EPS_BRAND_C7M)
states = max_multiplier - min_multiplier + 1;
@@ -453,6 +469,8 @@ MODULE_PARM_DESC(voltage_failsafe_off, "Disable current vs max voltage check");
module_param(ignore_acpi_limit, int, 0644);
MODULE_PARM_DESC(ignore_acpi_limit, "Don't check ACPI's processor speed limit");
#endif
+module_param(set_max_voltage, int, 0644);
+MODULE_PARM_DESC(set_max_voltage, "Set maximum CPU voltage (mV) C7-M only");
MODULE_AUTHOR("Rafal Bilski <rafalbilski@interia.pl>");
MODULE_DESCRIPTION("Enhanced PowerSaver driver for VIA C7 CPU's.");