summaryrefslogtreecommitdiffstats
path: root/debian/patches-rt/0054-cpufreq-drop-K8-s-driver-from-beeing-selected.patch
blob: 2e2f27606ea96bb4204731386f4affd7ceeffa85 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Date: Thu, 9 Apr 2015 15:23:01 +0200
Subject: [PATCH 054/351] cpufreq: drop K8's driver from beeing selected
Origin: https://git.kernel.org/cgit/linux/kernel/git/rt/linux-stable-rt.git/commit?id=cd711b3f7f067737c313778a19f497b70348423b

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.