[PATCH v4 5/7] cpufreq: Add compatibility hack to powernow-k8

[Matthew Garrett <mjg@redhat.com>]

cpufreq modules are often loaded from init scripts that assume that all
recent AMD systems will use powernow-k8, so we should ensure that loading
it triggers a load of acpi-cpufreq if the latter is built as a module.
This avoids the problem of users ending up without any cpufreq support
after the transition.

Signed-off-by: Matthew Garrett <mjg@redhat.com>
---
 drivers/cpufreq/powernow-k8.c |    6 +++++-
 1 files changed, 5 insertions(+), 1 deletions(-)

diff --git a/drivers/cpufreq/powernow-k8.c b/drivers/cpufreq/powernow-k8.c
index bce576d..8de4446 100644
--- a/drivers/cpufreq/powernow-k8.c
+++ b/drivers/cpufreq/powernow-k8.c
@@ -1549,8 +1549,12 @@ static int __cpuinit powernowk8_init(void)
 			supported_cpus++;
 	}
 
-	if (supported_cpus != num_online_cpus())
+	if (supported_cpus != num_online_cpus()) {
+		if (static_cpu_has(X86_FEATURE_HW_PSTATE))
+			request_module("acpi_cpufreq");
+
 		return -ENODEV;
+	}
 
 	printk(KERN_INFO PFX "Found %d %s (%d cpu cores) (" VERSION ")\n",
 		num_online_nodes(), boot_cpu_data.x86_model_id, supported_cpus);
-- 
1.7.6