From 8dc4f59d3d6db08c4b9ab5723d95e3542eaac829 Mon Sep 17 00:00:00 2001
Message-Id: <8dc4f59d3d6db08c4b9ab5723d95e3542eaac829.1592846147.git.zanussi@kernel.org>
In-Reply-To: <07cd0dbc80b976663c80755496a03f288decfe5a.1592846146.git.zanussi@kernel.org>
References: <07cd0dbc80b976663c80755496a03f288decfe5a.1592846146.git.zanussi@kernel.org>
From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Date: Thu, 9 Apr 2015 15:23:01 +0200
Subject: [PATCH 054/330] cpufreq: drop K8's driver from beeing selected
Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.19/older/patches-4.19.127-rt55.tar.xz

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>
---
 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.
-- 
2.17.1

