From: Thomas Renninger Date: Mon, 1 Sep 2008 12:27:04 +0000 (+0200) Subject: ACPI: cpufreq, processor: Detect old BIOS, not supporting CPU freq on a recent CPU. X-Git-Tag: v2.6.28-rc1~26^2~29^2~1 X-Git-Url: http://pilppa.com/gitweb/?a=commitdiff_plain;h=910dfae298f7b3dae0e9a52736182a3b0559ca35;p=linux-2.6-omap-h63xx.git 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 Signed-off-by: Andi Kleen Signed-off-by: Len Brown --- 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 #endif +#include #include #include @@ -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)