ACPI: cpufreq, processor: Detect old BIOS, not supporting CPU freq on a recent CPU.

[linux-2.6-omap-h63xx.git] / drivers / acpi / processor_perflib.c

diff --git a/drivers/acpi/processor_perflib.c b/drivers/acpi/processor_perflib.c
index 80e32093e977c6a3c5427e0746c1732a2282e017..242f8143008ab728e963fcba99dea7bc1e1e7bd7 100644 (file)
--- a/drivers/acpi/processor_perflib.c
+++ b/drivers/acpi/processor_perflib.c
@@ -38,6 +38,7 @@
 
 #include <asm/uaccess.h>
 #endif
+#include <asm/cpufeature.h>
 
 #include <acpi/acpi_bus.h>
 #include <acpi/processor.h>
@@ -71,7 +72,7 @@ static DEFINE_MUTEX(performance_mutex);
  *  1 -> ignore _PPC totally -> forced by user through boot param
  */
 static int ignore_ppc = -1;
-module_param(ignore_ppc, uint, 0644);
+module_param(ignore_ppc, int, 0644);
 MODULE_PARM_DESC(ignore_ppc, "If the frequency of your machine gets wrongly" \
                 "limited by BIOS, this should help");
 
@@ -334,7 +335,6 @@ static int acpi_processor_get_performance_info(struct acpi_processor *pr)
        acpi_status status = AE_OK;
        acpi_handle handle = NULL;
 
-
        if (!pr || !pr->performance || !pr->handle)
                return -EINVAL;
 
@@ -347,13 +347,25 @@ static int acpi_processor_get_performance_info(struct acpi_processor *pr)
 
        result = acpi_processor_get_performance_control(pr);
        if (result)
-               return result;
+               goto update_bios;
 
        result = acpi_processor_get_performance_states(pr);
        if (result)
-               return result;
+               goto update_bios;
 
        return 0;
+
+       /*
+        * Having _PPC but missing frequencies (_PSS, _PCT) is a very good hint that
+        * the BIOS is older than the CPU and does not know its frequencies
+        */
+ update_bios:
+       if (ACPI_SUCCESS(acpi_get_handle(pr->handle, "_PPC", &handle))){
+               if(boot_cpu_has(X86_FEATURE_EST))
+                       printk(KERN_WARNING FW_BUG "BIOS needs update for CPU "
+                              "frequency support\n");
+       }
+       return result;
 }
 
 int acpi_processor_notify_smm(struct module *calling_module)