cpufreq: move freq change notifications to cpufreq core

Most of the drivers do following in their ->target_index() routines:

	struct cpufreq_freqs freqs;
	freqs.old = old freq...
	freqs.new = new freq...

	cpufreq_notify_transition(policy, &freqs, CPUFREQ_PRECHANGE);

	/* Change rate here */

	cpufreq_notify_transition(policy, &freqs, CPUFREQ_POSTCHANGE);

This is replicated over all cpufreq drivers today and there doesn't exists a
good enough reason why this shouldn't be moved to cpufreq core instead.

There are few special cases though, like exynos5440, which doesn't do everything
on the call to ->target_index() routine and call some kind of bottom halves for
doing this work, work/tasklet/etc..

They may continue doing notification from their own code as flag:
CPUFREQ_ASYNC_NOTIFICATION is already set for them.

All drivers are also modified in this patch to avoid breaking 'git bisect', as
double notification would happen otherwise.

Acked-by: Hans-Christian Egtvedt <egtvedt@samfundet.no>
Acked-by: Jesper Nilsson <jesper.nilsson@axis.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Russell King <linux@arm.linux.org.uk>
Acked-by: Stephen Warren <swarren@nvidia.com>
Tested-by: Andrew Lunn <andrew@lunn.ch>
Tested-by: Nicolas Pitre <nicolas.pitre@linaro.org>
Reviewed-by: Lan Tianyu <tianyu.lan@intel.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

1 files changed, 3 insertions, 20 deletions

diff --git a/drivers/cpufreq/e_powersaver.c b/drivers/cpufreq/e_powersaver.c
index b39c4ef..9012b8b 100644
--- a/drivers/cpufreq/e_powersaver.c
+++ b/drivers/cpufreq/e_powersaver.c
@@ -107,15 +107,9 @@ static int eps_set_state(struct eps_cpu_data *centaur,
 			 struct cpufreq_policy *policy,
 			 u32 dest_state)
 {
-	struct cpufreq_freqs freqs;
 	u32 lo, hi;
-	int err = 0;
 	int i;
 
-	freqs.old = eps_get(policy->cpu);
-	freqs.new = centaur->fsb * ((dest_state >> 8) & 0xff);
-	cpufreq_notify_transition(policy, &freqs, CPUFREQ_PRECHANGE);
-
 	/* Wait while CPU is busy */
 	rdmsr(MSR_IA32_PERF_STATUS, lo, hi);
 	i = 0;
@@ -124,8 +118,7 @@ static int eps_set_state(struct eps_cpu_data *centaur,
 		rdmsr(MSR_IA32_PERF_STATUS, lo, hi);
 		i++;
 		if (unlikely(i > 64)) {
-			err = -ENODEV;
-			goto postchange;
+			return -ENODEV;
 		}
 	}
 	/* Set new multiplier and voltage */
@@ -137,16 +130,10 @@ static int eps_set_state(struct eps_cpu_data *centaur,
 		rdmsr(MSR_IA32_PERF_STATUS, lo, hi);
 		i++;
 		if (unlikely(i > 64)) {
-			err = -ENODEV;
-			goto postchange;
+			return -ENODEV;
 		}
 	} while (lo & ((1 << 16) | (1 << 17)));
 
-	/* Return current frequency */
-postchange:
-	rdmsr(MSR_IA32_PERF_STATUS, lo, hi);
-	freqs.new = centaur->fsb * ((lo >> 8) & 0xff);
-
 #ifdef DEBUG
 	{
 	u8 current_multiplier, current_voltage;
@@ -161,11 +148,7 @@ postchange:
 		current_multiplier);
 	}
 #endif
-	if (err)
-		freqs.new = freqs.old;
-
-	cpufreq_notify_transition(policy, &freqs, CPUFREQ_POSTCHANGE);
-	return err;
+	return 0;
 }
 
 static int eps_target(struct cpufreq_policy *policy, unsigned int index)