cpufreq: drop K8's driver from beeing selected

Ralf posted a picture of a backtrace from

| powernowk8_target_fn() -> transition_frequency_fidvid() and then at the
| end:
| 932         policy = cpufreq_cpu_get(smp_processor_id());
| 933         cpufreq_cpu_put(policy);

crashing the system on -RT. I assumed that policy was a NULL pointer but
was rulled out. Since Ralf can't do any more investigations on this and
I have no machine with this, I simply switch it off.

Reported-by:  Ralf Mardorf <ralf.mardorf@alice-dsl.net>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>

diff --git a/drivers/cpufreq/Kconfig.x86 b/drivers/cpufreq/Kconfig.x86
index c59bdcb83217071087cc0a90ef62e5cd01ce38d7..8f23161d80bef6e87e957dc64120527ef6396b95 100644 (file)
--- a/drivers/cpufreq/Kconfig.x86
+++ b/drivers/cpufreq/Kconfig.x86
@@ -123,7 +123,7 @@ config X86_POWERNOW_K7_ACPI
 
 config X86_POWERNOW_K8
        tristate "AMD Opteron/Athlon64 PowerNow!"
-       depends on ACPI && ACPI_PROCESSOR && X86_ACPI_CPUFREQ
+       depends on ACPI && ACPI_PROCESSOR && X86_ACPI_CPUFREQ && !PREEMPT_RT_BASE
        help
          This adds the CPUFreq driver for K8/early Opteron/Athlon64 processors.
          Support for K10 and newer processors is now in acpi-cpufreq.