cpufreq acpi: only call _PPC after cpufreq ACPI init funcs got called already

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>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/arch/powerpc/platforms/cell/cbe_cpufreq_pmi.c b/arch/powerpc/platforms/cell/cbe_cpufreq_pmi.c
index 69288f6..3233fe8 100644 (file)
--- 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_block *nb,
        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);
 

diff --git a/drivers/acpi/processor_perflib.c b/drivers/acpi/processor_perflib.c
index b474996..e98071a 100644 (file)
--- 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 frequency of your machine gets wrongly" \
 #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(struct notifier_block *nb,
        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;
 

diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c
index 8d6a3ff..8a67f16 100644 (file)
--- a/drivers/cpufreq/cpufreq.c
+++ b/drivers/cpufreq/cpufreq.c
@@ -825,6 +825,9 @@ static int cpufreq_add_dev(struct sys_device *sys_dev)
        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

diff --git a/include/linux/cpufreq.h b/include/linux/cpufreq.h
index 2270ca5..6fd5668 100644 (file)
--- a/include/linux/cpufreq.h
+++ b/include/linux/cpufreq.h
@@ -106,6 +106,7 @@ 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 */