From: Sebastian Andrzej Siewior Date: Thu, 9 Apr 2015 15:23:01 +0200 Subject: [PATCH 054/353] cpufreq: drop K8's driver from beeing selected Origin: https://git.kernel.org/cgit/linux/kernel/git/rt/linux-stable-rt.git/commit?id=7644f056b07841ff9b1f0984caed7ed5db699030 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 Signed-off-by: Sebastian Andrzej Siewior --- drivers/cpufreq/Kconfig.x86 | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/cpufreq/Kconfig.x86 b/drivers/cpufreq/Kconfig.x86 index 35f71825b7f3..bb4a6160d0f7 100644 --- a/drivers/cpufreq/Kconfig.x86 +++ b/drivers/cpufreq/Kconfig.x86 @@ -125,7 +125,7 @@ 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.