diff options
| author | Thomas Renninger <trenn@suse.de> | 2008-09-01 14:27:04 +0200 |
|---|---|---|
| committer | Len Brown <len.brown@intel.com> | 2008-09-22 18:48:07 -0400 |
| commit | 910dfae298f7b3dae0e9a52736182a3b0559ca35 (patch) | |
| tree | 6fd4823b6e75afb2861004f464e0842370f983ef /drivers/acpi/processor_perflib.c | |
| parent | a0ad05c75aa362c91f4d9cd91ff375a739574dd8 (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.c | 18 |
1 files changed, 15 insertions, 3 deletions
diff --git a/drivers/acpi/processor_perflib.c b/drivers/acpi/processor_perflib.c index 80c251ec6d2..242f8143008 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) |