cpufreq: Mark ARM drivers with CPUFREQ_NEED_INITIAL_FREQ_CHECK flag

Sometimes boot loaders set CPU frequency to a value outside of frequency table
present with cpufreq core. In such cases CPU might be unstable if it has to run
on that frequency for long duration of time and so its better to set it to a
frequency which is specified in frequency table.

On some systems we can't really say what frequency we're running at the moment
and so for these we shouldn't check if we are running at a frequency present in
frequency table. And so we really can't force this for all the cpufreq drivers.

Hence we are created another flag here: CPUFREQ_NEED_INITIAL_FREQ_CHECK that
will be marked by platforms which want to go for this check at boot time.

Initially this is done for all ARM platforms but others may follow if required.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

20 files changed, 31 insertions, 13 deletions

diff --git a/drivers/cpufreq/arm_big_little.c b/drivers/cpufreq/arm_big_little.c
index 5519933813e..72f87e9317e 100644
--- a/drivers/cpufreq/arm_big_little.c
+++ b/drivers/cpufreq/arm_big_little.c
@@ -488,7 +488,8 @@ static int bL_cpufreq_exit(struct cpufreq_policy *policy)
 static struct cpufreq_driver bL_cpufreq_driver = {
 	.name			= "arm-big-little",
 	.flags			= CPUFREQ_STICKY |
-					CPUFREQ_HAVE_GOVERNOR_PER_POLICY,
+					CPUFREQ_HAVE_GOVERNOR_PER_POLICY |
+					CPUFREQ_NEED_INITIAL_FREQ_CHECK,
 	.verify			= cpufreq_generic_frequency_table_verify,
 	.target_index		= bL_cpufreq_set_target,
 	.get			= bL_cpufreq_get_rate,
diff --git a/drivers/cpufreq/davinci-cpufreq.c b/drivers/cpufreq/davinci-cpufreq.c
index 5e8a854381b..04f3390a7a2 100644
--- a/drivers/cpufreq/davinci-cpufreq.c
+++ b/drivers/cpufreq/davinci-cpufreq.c
@@ -126,7 +126,7 @@ static int davinci_cpu_init(struct cpufreq_policy *policy)
 }
 
 static struct cpufreq_driver davinci_driver = {
-	.flags		= CPUFREQ_STICKY,
+	.flags		= CPUFREQ_STICKY | CPUFREQ_NEED_INITIAL_FREQ_CHECK,
 	.verify		= davinci_verify_speed,
 	.target_index	= davinci_target,
 	.get		= davinci_getspeed,
diff --git a/drivers/cpufreq/dbx500-cpufreq.c b/drivers/cpufreq/dbx500-cpufreq.c
index 0e67ab96321..21d9898e000 100644
--- a/drivers/cpufreq/dbx500-cpufreq.c
+++ b/drivers/cpufreq/dbx500-cpufreq.c
@@ -48,7 +48,8 @@ static int dbx500_cpufreq_init(struct cpufreq_policy *policy)
 }
 
 static struct cpufreq_driver dbx500_cpufreq_driver = {
-	.flags  = CPUFREQ_STICKY | CPUFREQ_CONST_LOOPS,
+	.flags  = CPUFREQ_STICKY | CPUFREQ_CONST_LOOPS |
+			CPUFREQ_NEED_INITIAL_FREQ_CHECK,
 	.verify = cpufreq_generic_frequency_table_verify,
 	.target_index = dbx500_cpufreq_target,
 	.get    = dbx500_cpufreq_getspeed,
diff --git a/drivers/cpufreq/exynos-cpufreq.c b/drivers/cpufreq/exynos-cpufreq.c
index f3c22874da7..85e67dc6d07 100644
--- a/drivers/cpufreq/exynos-cpufreq.c
+++ b/drivers/cpufreq/exynos-cpufreq.c
@@ -218,7 +218,7 @@ static int exynos_cpufreq_cpu_init(struct cpufreq_policy *policy)
 }
 
 static struct cpufreq_driver exynos_driver = {
-	.flags		= CPUFREQ_STICKY,
+	.flags		= CPUFREQ_STICKY | CPUFREQ_NEED_INITIAL_FREQ_CHECK,
 	.verify		= cpufreq_generic_frequency_table_verify,
 	.target_index	= exynos_target,
 	.get		= exynos_getspeed,
diff --git a/drivers/cpufreq/exynos5440-cpufreq.c b/drivers/cpufreq/exynos5440-cpufreq.c
index 76bef8b078c..ffe6faea3a5 100644
--- a/drivers/cpufreq/exynos5440-cpufreq.c
+++ b/drivers/cpufreq/exynos5440-cpufreq.c
@@ -312,7 +312,8 @@ static int exynos_cpufreq_cpu_init(struct cpufreq_policy *policy)
 }
 
 static struct cpufreq_driver exynos_driver = {
-	.flags		= CPUFREQ_STICKY | CPUFREQ_ASYNC_NOTIFICATION,
+	.flags		= CPUFREQ_STICKY | CPUFREQ_ASYNC_NOTIFICATION |
+				CPUFREQ_NEED_INITIAL_FREQ_CHECK,
 	.verify		= cpufreq_generic_frequency_table_verify,
 	.target_index	= exynos_target,
 	.get		= exynos_getspeed,
diff --git a/drivers/cpufreq/imx6q-cpufreq.c b/drivers/cpufreq/imx6q-cpufreq.c
index 564a26523eb..2938257b8c1 100644
--- a/drivers/cpufreq/imx6q-cpufreq.c
+++ b/drivers/cpufreq/imx6q-cpufreq.c
@@ -143,6 +143,7 @@ static int imx6q_cpufreq_init(struct cpufreq_policy *policy)
 }
 
 static struct cpufreq_driver imx6q_cpufreq_driver = {
+	.flags = CPUFREQ_NEED_INITIAL_FREQ_CHECK,
 	.verify = cpufreq_generic_frequency_table_verify,
 	.target_index = imx6q_set_target,
 	.get = imx6q_get_speed,
diff --git a/drivers/cpufreq/integrator-cpufreq.c b/drivers/cpufreq/integrator-cpufreq.c
index 7d8ab000d31..0e27844e8c2 100644
--- a/drivers/cpufreq/integrator-cpufreq.c
+++ b/drivers/cpufreq/integrator-cpufreq.c
@@ -190,6 +190,7 @@ static int integrator_cpufreq_init(struct cpufreq_policy *policy)
 }
 
 static struct cpufreq_driver integrator_driver = {
+	.flags		= CPUFREQ_NEED_INITIAL_FREQ_CHECK,
 	.verify		= integrator_verify_policy,
 	.target		= integrator_set_target,
 	.get		= integrator_get,
diff --git a/drivers/cpufreq/kirkwood-cpufreq.c b/drivers/cpufreq/kirkwood-cpufreq.c
index 0767a4e29df..eb7abe345b5 100644
--- a/drivers/cpufreq/kirkwood-cpufreq.c
+++ b/drivers/cpufreq/kirkwood-cpufreq.c
@@ -97,6 +97,7 @@ static int kirkwood_cpufreq_cpu_init(struct cpufreq_policy *policy)
 }
 
 static struct cpufreq_driver kirkwood_cpufreq_driver = {
+	.flags	= CPUFREQ_NEED_INITIAL_FREQ_CHECK,
 	.get	= kirkwood_cpufreq_get_cpu_frequency,
 	.verify	= cpufreq_generic_frequency_table_verify,
 	.target_index = kirkwood_cpufreq_target,
diff --git a/drivers/cpufreq/omap-cpufreq.c b/drivers/cpufreq/omap-cpufreq.c
index a0acd0bfba4..5de1e5f73ec 100644
--- a/drivers/cpufreq/omap-cpufreq.c
+++ b/drivers/cpufreq/omap-cpufreq.c
@@ -162,7 +162,7 @@ static int omap_cpu_exit(struct cpufreq_policy *policy)
 }
 
 static struct cpufreq_driver omap_driver = {
-	.flags		= CPUFREQ_STICKY,
+	.flags		= CPUFREQ_STICKY | CPUFREQ_NEED_INITIAL_FREQ_CHECK,
 	.verify		= cpufreq_generic_frequency_table_verify,
 	.target_index	= omap_target,
 	.get		= omap_getspeed,
diff --git a/drivers/cpufreq/pxa2xx-cpufreq.c b/drivers/cpufreq/pxa2xx-cpufreq.c
index 0a0f4369636..a9195a86b06 100644
--- a/drivers/cpufreq/pxa2xx-cpufreq.c
+++ b/drivers/cpufreq/pxa2xx-cpufreq.c
@@ -423,6 +423,7 @@ static int pxa_cpufreq_init(struct cpufreq_policy *policy)
 }
 
 static struct cpufreq_driver pxa_cpufreq_driver = {
+	.flags	= CPUFREQ_NEED_INITIAL_FREQ_CHECK,
 	.verify	= cpufreq_generic_frequency_table_verify,
 	.target_index = pxa_set_target,
 	.init	= pxa_cpufreq_init,
diff --git a/drivers/cpufreq/pxa3xx-cpufreq.c b/drivers/cpufreq/pxa3xx-cpufreq.c
index 93840048dd1..3785687e9d7 100644
--- a/drivers/cpufreq/pxa3xx-cpufreq.c
+++ b/drivers/cpufreq/pxa3xx-cpufreq.c
@@ -201,6 +201,7 @@ static int pxa3xx_cpufreq_init(struct cpufreq_policy *policy)
 }
 
 static struct cpufreq_driver pxa3xx_cpufreq_driver = {
+	.flags		= CPUFREQ_NEED_INITIAL_FREQ_CHECK,
 	.verify		= cpufreq_generic_frequency_table_verify,
 	.target_index	= pxa3xx_cpufreq_set,
 	.init		= pxa3xx_cpufreq_init,
diff --git a/drivers/cpufreq/s3c2416-cpufreq.c b/drivers/cpufreq/s3c2416-cpufreq.c
index 8d904a00027..826b8be2309 100644
--- a/drivers/cpufreq/s3c2416-cpufreq.c
+++ b/drivers/cpufreq/s3c2416-cpufreq.c
@@ -481,7 +481,7 @@ err_hclk:
 }
 
 static struct cpufreq_driver s3c2416_cpufreq_driver = {
-	.flags          = 0,
+	.flags		= CPUFREQ_NEED_INITIAL_FREQ_CHECK,
 	.verify		= cpufreq_generic_frequency_table_verify,
 	.target_index	= s3c2416_cpufreq_set_target,
 	.get		= s3c2416_cpufreq_get_speed,
diff --git a/drivers/cpufreq/s3c24xx-cpufreq.c b/drivers/cpufreq/s3c24xx-cpufreq.c
index 35fa697e615..6a1bf96deec 100644
--- a/drivers/cpufreq/s3c24xx-cpufreq.c
+++ b/drivers/cpufreq/s3c24xx-cpufreq.c
@@ -448,7 +448,7 @@ static int s3c_cpufreq_resume(struct cpufreq_policy *policy)
 #endif
 
 static struct cpufreq_driver s3c24xx_driver = {
-	.flags		= CPUFREQ_STICKY,
+	.flags		= CPUFREQ_STICKY | CPUFREQ_NEED_INITIAL_FREQ_CHECK,
 	.target		= s3c_cpufreq_target,
 	.get		= s3c_cpufreq_get,
 	.init		= s3c_cpufreq_init,
diff --git a/drivers/cpufreq/s3c64xx-cpufreq.c b/drivers/cpufreq/s3c64xx-cpufreq.c
index 67e302eeefe..8435f45d7e9 100644
--- a/drivers/cpufreq/s3c64xx-cpufreq.c
+++ b/drivers/cpufreq/s3c64xx-cpufreq.c
@@ -226,7 +226,7 @@ static int s3c64xx_cpufreq_driver_init(struct cpufreq_policy *policy)
 }
 
 static struct cpufreq_driver s3c64xx_cpufreq_driver = {
-	.flags          = 0,
+	.flags		= CPUFREQ_NEED_INITIAL_FREQ_CHECK,
 	.verify		= cpufreq_generic_frequency_table_verify,
 	.target_index	= s3c64xx_cpufreq_set_target,
 	.get		= s3c64xx_cpufreq_get_speed,
diff --git a/drivers/cpufreq/s5pv210-cpufreq.c b/drivers/cpufreq/s5pv210-cpufreq.c
index e3973dae28a..ccd548c6f0c 100644
--- a/drivers/cpufreq/s5pv210-cpufreq.c
+++ b/drivers/cpufreq/s5pv210-cpufreq.c
@@ -560,7 +560,7 @@ static int s5pv210_cpufreq_reboot_notifier_event(struct notifier_block *this,
 }
 
 static struct cpufreq_driver s5pv210_driver = {
-	.flags		= CPUFREQ_STICKY,
+	.flags		= CPUFREQ_STICKY | CPUFREQ_NEED_INITIAL_FREQ_CHECK,
 	.verify		= cpufreq_generic_frequency_table_verify,
 	.target_index	= s5pv210_target,
 	.get		= s5pv210_getspeed,
diff --git a/drivers/cpufreq/sa1100-cpufreq.c b/drivers/cpufreq/sa1100-cpufreq.c
index 623da742f8e..728eab77e8e 100644
--- a/drivers/cpufreq/sa1100-cpufreq.c
+++ b/drivers/cpufreq/sa1100-cpufreq.c
@@ -201,7 +201,7 @@ static int __init sa1100_cpu_init(struct cpufreq_policy *policy)
 }
 
 static struct cpufreq_driver sa1100_driver __refdata = {
-	.flags		= CPUFREQ_STICKY,
+	.flags		= CPUFREQ_STICKY | CPUFREQ_NEED_INITIAL_FREQ_CHECK,
 	.verify		= cpufreq_generic_frequency_table_verify,
 	.target_index	= sa1100_target,
 	.get		= sa11x0_getspeed,
diff --git a/drivers/cpufreq/sa1110-cpufreq.c b/drivers/cpufreq/sa1110-cpufreq.c
index 2c2b2e601d1..546376719d8 100644
--- a/drivers/cpufreq/sa1110-cpufreq.c
+++ b/drivers/cpufreq/sa1110-cpufreq.c
@@ -312,7 +312,7 @@ static int __init sa1110_cpu_init(struct cpufreq_policy *policy)
 /* sa1110_driver needs __refdata because it must remain after init registers
  * it with cpufreq_register_driver() */
 static struct cpufreq_driver sa1110_driver __refdata = {
-	.flags		= CPUFREQ_STICKY,
+	.flags		= CPUFREQ_STICKY | CPUFREQ_NEED_INITIAL_FREQ_CHECK,
 	.verify		= cpufreq_generic_frequency_table_verify,
 	.target_index	= sa1110_target,
 	.get		= sa11x0_getspeed,
diff --git a/drivers/cpufreq/spear-cpufreq.c b/drivers/cpufreq/spear-cpufreq.c
index 45ea4c09454..c7525fe3340 100644
--- a/drivers/cpufreq/spear-cpufreq.c
+++ b/drivers/cpufreq/spear-cpufreq.c
@@ -162,7 +162,7 @@ static int spear_cpufreq_init(struct cpufreq_policy *policy)
 
 static struct cpufreq_driver spear_cpufreq_driver = {
 	.name		= "cpufreq-spear",
-	.flags		= CPUFREQ_STICKY,
+	.flags		= CPUFREQ_STICKY | CPUFREQ_NEED_INITIAL_FREQ_CHECK,
 	.verify		= cpufreq_generic_frequency_table_verify,
 	.target_index	= spear_cpufreq_target,
 	.get		= spear_cpufreq_get,
diff --git a/drivers/cpufreq/tegra-cpufreq.c b/drivers/cpufreq/tegra-cpufreq.c
index b7309c37033..01b5578ffec 100644
--- a/drivers/cpufreq/tegra-cpufreq.c
+++ b/drivers/cpufreq/tegra-cpufreq.c
@@ -214,6 +214,7 @@ static int tegra_cpu_exit(struct cpufreq_policy *policy)
 }
 
 static struct cpufreq_driver tegra_cpufreq_driver = {
+	.flags		= CPUFREQ_NEED_INITIAL_FREQ_CHECK,
 	.verify		= cpufreq_generic_frequency_table_verify,
 	.target_index	= tegra_target,
 	.get		= tegra_getspeed,
diff --git a/include/linux/cpufreq.h b/include/linux/cpufreq.h
index 88aa0f342e8..91b8c84e8cd 100644
--- a/include/linux/cpufreq.h
+++ b/include/linux/cpufreq.h
@@ -252,6 +252,15 @@ struct cpufreq_driver {
  */
 #define CPUFREQ_ASYNC_NOTIFICATION  (1 << 4)
 
+/*
+ * Set by drivers which want cpufreq core to check if CPU is running at a
+ * frequency present in freq-table exposed by the driver. For these drivers if
+ * CPU is found running at an out of table freq, we will try to set it to a freq
+ * from the table. And if that fails, we will stop further boot process by
+ * issuing a BUG_ON().
+ */
+#define CPUFREQ_NEED_INITIAL_FREQ_CHECK	(1 << 5)
+
 int cpufreq_register_driver(struct cpufreq_driver *driver_data);
 int cpufreq_unregister_driver(struct cpufreq_driver *driver_data);