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authorThomas Renninger <trenn@suse.de>2008-09-01 14:27:04 +0200
committerLen Brown <len.brown@intel.com>2008-09-22 18:48:07 -0400
commit910dfae298f7b3dae0e9a52736182a3b0559ca35 (patch)
tree6fd4823b6e75afb2861004f464e0842370f983ef /drivers/acpi/processor_perflib.c
parenta0ad05c75aa362c91f4d9cd91ff375a739574dd8 (diff)
ACPI: cpufreq, processor: Detect old BIOS, not supporting CPU freq on a recent CPU.
On Intel CPUs it is rather common and a good hint that BIOSes which do provide _PPC func, but not the frequencies itself in _PSS function, are old and need to be updated for CPU freq support. Tell the user/vendor he has a BIOS/firmware problem. Make use of FW_BUG interface to give vendors and users the ability to automatically check with (or let linuxfirmwarekit do that): dmesg |grep "Firmware Bug" Signed-off-by: Thomas Renninger <trenn@suse.de> Signed-off-by: Andi Kleen <ak@linux.intel.com> Signed-off-by: Len Brown <len.brown@intel.com>
Diffstat (limited to 'drivers/acpi/processor_perflib.c')
-rw-r--r--drivers/acpi/processor_perflib.c18
1 files changed, 15 insertions, 3 deletions
diff --git a/drivers/acpi/processor_perflib.c b/drivers/acpi/processor_perflib.c
index 80c251ec6d2a..242f8143008a 100644
--- 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>
@@ -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)