2.6.26 -stable review patch. If anyone has any objections, please let
us know.
------------------
From: Thomas Renninger <trenn@suse.de>
commit a1531acd43310a7e4571d52e8846640667f4c74b upstream
Ingo Molnar provided a fix to not call _PPC at processor driver
initialization time in "[PATCH] ACPI: fix cpufreq regression" (git
commit e4233dec749a3519069d9390561b5636a75c7579)
But it can still happen that _PPC is called at processor driver
initialization time.
This patch should make sure that this is not possible anymore.
Signed-off-by: Thomas Renninger <trenn@suse.de>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Len Brown <lenb@kernel.org>
Cc: Dave Jones <davej@codemonkey.org.uk>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
---
arch/powerpc/platforms/cell/cbe_cpufreq_pmi.c | 6 ++++++
drivers/acpi/processor_perflib.c | 15 +++++++++++++--
drivers/cpufreq/cpufreq.c | 3 +++
include/linux/cpufreq.h | 1 +
4 files changed, 23 insertions(+), 2 deletions(-)
--- a/arch/powerpc/platforms/cell/cbe_cpufreq_pmi.c
+++ b/arch/powerpc/platforms/cell/cbe_cpufreq_pmi.c
@@ -96,6 +96,12 @@ static int pmi_notifier(struct notifier_
struct cpufreq_frequency_table *cbe_freqs;
u8 node;
+ /* Should this really be called for CPUFREQ_ADJUST, CPUFREQ_INCOMPATIBLE
+ * and CPUFREQ_NOTIFY policy events?)
+ */
+ if (event == CPUFREQ_START)
+ return 0;
+
cbe_freqs = cpufreq_frequency_get_table(policy->cpu);
node = cbe_cpu_to_node(policy->cpu);
--- a/drivers/acpi/processor_perflib.c
+++ b/drivers/acpi/processor_perflib.c
@@ -64,7 +64,13 @@ static DEFINE_MUTEX(performance_mutex);
* policy is adjusted accordingly.
*/
-static unsigned int ignore_ppc = 0;
+/* ignore_ppc:
+ * -1 -> cpufreq low level drivers not initialized -> _PSS, etc. not called yet
+ * ignore _PPC
+ * 0 -> cpufreq low level drivers initialized -> consider _PPC values
+ * 1 -> ignore _PPC totally -> forced by user through boot param
+ */
+static unsigned int ignore_ppc = -1;
module_param(ignore_ppc, uint, 0644);
MODULE_PARM_DESC(ignore_ppc, "If the frequency of your machine gets wrongly" \
"limited by BIOS, this should help");
@@ -72,7 +78,7 @@ MODULE_PARM_DESC(ignore_ppc, "If the fre
#define PPC_REGISTERED 1
#define PPC_IN_USE 2
-static int acpi_processor_ppc_status = 0;
+static int acpi_processor_ppc_status;
static int acpi_processor_ppc_notifier(struct notifier_block *nb,
unsigned long event, void *data)
@@ -81,6 +87,11 @@ static int acpi_processor_ppc_notifier(s
struct acpi_processor *pr;
unsigned int ppc = 0;
+ if (event == CPUFREQ_START && ignore_ppc <= 0) {
+ ignore_ppc = 0;
+ return 0;
+ }
+
if (ignore_ppc)
return 0;
--- a/drivers/cpufreq/cpufreq.c
+++ b/drivers/cpufreq/cpufreq.c
@@ -825,6 +825,9 @@ static int cpufreq_add_dev(struct sys_de
policy->user_policy.min = policy->cpuinfo.min_freq;
policy->user_policy.max = policy->cpuinfo.max_freq;
+ blocking_notifier_call_chain(&cpufreq_policy_notifier_list,
+ CPUFREQ_START, policy);
+
#ifdef CONFIG_SMP
#ifdef CONFIG_HOTPLUG_CPU
--- a/include/linux/cpufreq.h
+++ b/include/linux/cpufreq.h
@@ -109,6 +109,7 @@ struct cpufreq_policy {
#define CPUFREQ_ADJUST (0)
#define CPUFREQ_INCOMPATIBLE (1)
#define CPUFREQ_NOTIFY (2)
+#define CPUFREQ_START (3)
#define CPUFREQ_SHARED_TYPE_NONE (0) /* None */
#define CPUFREQ_SHARED_TYPE_HW (1) /* HW does needed coordination */
--
--
