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authorMatthew Garrett <mjg59@srcf.ucam.org>2013-01-20 10:24:26 +0000
committerRafael J. Wysocki <rafael.j.wysocki@intel.com>2013-02-02 00:01:14 +0100
commitc40a4518166b6c500c844579ec7069d4a0419f30 (patch)
tree43295c9555e15bcba7ab2a3c12dd9ffc9f6fef87 /drivers/cpufreq/acpi-cpufreq.c
parentd5aaffa9dd531c978c6f3fea06a2972653bd7fc8 (diff)
acpi-cpufreq: Do not load on K8
de3ed81d746d ("[CPUFREQ] Change link order of x86 cpufreq modules") changed cpufreq drivers link order so that powernow-k8 gets loaded first due to earlier K8s having BIOS bugs. However, now that acpi-cpufreq supports both AMD and Intel CPUs with HW P-states, we want to load it first, so that cases where acpi-cpufreq and powernow-k8 are both built-in and powernow-k8 initializing first, can be addressed. So, make sure that even if acpi-cpufreq gets loaded first, it errors out on K8s and powernow-k8 can be loaded then successfully. Signed-off-by: Matthew Garrett <mjg59@srcf.ucam.org> References: http://lkml.kernel.org/r/20130118162347.GA31499@srcf.ucam.org Signed-off-by: Borislav Petkov <bp@suse.de> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Diffstat (limited to 'drivers/cpufreq/acpi-cpufreq.c')
-rw-r--r--drivers/cpufreq/acpi-cpufreq.c6
1 files changed, 6 insertions, 0 deletions
diff --git a/drivers/cpufreq/acpi-cpufreq.c b/drivers/cpufreq/acpi-cpufreq.c
index 7b0d49d78c61..22f9b47c5c74 100644
--- a/drivers/cpufreq/acpi-cpufreq.c
+++ b/drivers/cpufreq/acpi-cpufreq.c
@@ -762,6 +762,12 @@ static int acpi_cpufreq_cpu_init(struct cpufreq_policy *policy)
switch (perf->control_register.space_id) {
case ACPI_ADR_SPACE_SYSTEM_IO:
+ if (boot_cpu_data.x86_vendor == X86_VENDOR_AMD &&
+ boot_cpu_data.x86 == 0xf) {
+ pr_debug("AMD K8 systems must use native drivers.\n");
+ result = -ENODEV;
+ goto err_unreg;
+ }
pr_debug("SYSTEM IO addr space\n");
data->cpu_feature = SYSTEM_IO_CAPABLE;
break;