---

yaml
---
r: 172547
b: refs/heads/master
c: 43f1069
h: refs/heads/master
i:
  172545: 94387d5
  172543: ebc1ce3
v: v3

[refs]

@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 383af9c2586e0c51e27ed4f186a2f23f8e889054
+refs/heads/master: 43f1069ef9af9a0b1fa1a1d6b49b2b05e1efc998

trunk/arch/arm/plat-s3c64xx/cpufreq.c

@@ -19,6 +19,7 @@
 
 static struct clk *armclk;
 static struct regulator *vddarm;
+static unsigned long regulator_latency;
 
 #ifdef CONFIG_CPU_S3C6410
 struct s3c64xx_dvfs {
@@ -141,7 +142,7 @@ static int s3c64xx_cpufreq_set_target(struct cpufreq_policy *policy,
 }
 
 #ifdef CONFIG_REGULATOR
-static void __init s3c64xx_cpufreq_constrain_voltages(void)
+static void __init s3c64xx_cpufreq_config_regulator(void)
 {
 	int count, v, i, found;
 	struct cpufreq_frequency_table *freq;
@@ -150,11 +151,10 @@ static void __init s3c64xx_cpufreq_constrain_voltages(void)
 	count = regulator_count_voltages(vddarm);
 	if (count < 0) {
 		pr_err("cpufreq: Unable to check supported voltages\n");
-		return;
 	}
 
 	freq = s3c64xx_freq_table;
-	while (freq->frequency != CPUFREQ_TABLE_END) {
+	while (count > 0 && freq->frequency != CPUFREQ_TABLE_END) {
 		if (freq->frequency == CPUFREQ_ENTRY_INVALID)
 			continue;
 
@@ -175,6 +175,10 @@ static void __init s3c64xx_cpufreq_constrain_voltages(void)
 
 		freq++;
 	}
+
+	/* Guess based on having to do an I2C/SPI write; in future we
+	 * will be able to query the regulator performance here. */
+	regulator_latency = 1 * 1000 * 1000;
 }
 #endif
 
@@ -206,7 +210,7 @@ static int __init s3c64xx_cpufreq_driver_init(struct cpufreq_policy *policy)
 		pr_err("cpufreq: Only frequency scaling available\n");
 		vddarm = NULL;
 	} else {
-		s3c64xx_cpufreq_constrain_voltages();
+		s3c64xx_cpufreq_config_regulator();
 	}
 #endif
 
@@ -233,9 +237,11 @@ static int __init s3c64xx_cpufreq_driver_init(struct cpufreq_policy *policy)
 
 	policy->cur = clk_get_rate(armclk) / 1000;
 
-	/* Pick a conservative guess in ns: we'll need ~1 I2C/SPI
-	 * write plus clock reprogramming. */
-	policy->cpuinfo.transition_latency = 2 * 1000 * 1000;
+	/* Datasheet says PLL stabalisation time (if we were to use
+	 * the PLLs, which we don't currently) is ~300us worst case,
+	 * but add some fudge.
+	 */
+	policy->cpuinfo.transition_latency = (500 * 1000) + regulator_latency;
 
 	ret = cpufreq_frequency_table_cpuinfo(policy, s3c64xx_freq_table);
 	if (ret != 0) {