From c40a4518166b6c500c844579ec7069d4a0419f30 Mon Sep 17 00:00:00 2001 From: Matthew Garrett Date: Sun, 20 Jan 2013 10:24:26 +0000 Subject: [PATCH] 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 References: http://lkml.kernel.org/r/20130118162347.GA31499@srcf.ucam.org Signed-off-by: Borislav Petkov Signed-off-by: Rafael J. Wysocki --- drivers/cpufreq/acpi-cpufreq.c | 6 ++++++ 1 file changed, 6 insertions(+) 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; -- 2.11.0