Merge tag 'mxs-fixes-3.9-4' of git://git.linaro.org/people/shawnguo/linux-2.6 into fixes

From Shawn Guo <shawn.guo@linaro.org>:

The mxs fixes for 3.9, take 4:
 - A couple mxs boards that run I2C at 400 kHz experience some unstable
   issue occasionally.  Slow down the clock speed to have I2C work
   reliably.

* tag 'mxs-fixes-3.9-4' of git://git.linaro.org/people/shawnguo/linux-2.6:
  ARM: mxs: Slow down the I2C clock speed

Signed-off-by: Arnd Bergmann <arnd@arndb.de>

1 files changed, 30 insertions, 4 deletions

diff --git a/drivers/cpufreq/intel_pstate.c b/drivers/cpufreq/intel_pstate.c
index f6dd1e76112..ad72922919e 100644
--- a/drivers/cpufreq/intel_pstate.c
+++ b/drivers/cpufreq/intel_pstate.c
@@ -358,14 +358,14 @@ static void intel_pstate_sysfs_expose_params(void)
 static int intel_pstate_min_pstate(void)
 {
 	u64 value;
-	rdmsrl(0xCE, value);
+	rdmsrl(MSR_PLATFORM_INFO, value);
 	return (value >> 40) & 0xFF;
 }
 
 static int intel_pstate_max_pstate(void)
 {
 	u64 value;
-	rdmsrl(0xCE, value);
+	rdmsrl(MSR_PLATFORM_INFO, value);
 	return (value >> 8) & 0xFF;
 }
 
@@ -373,7 +373,7 @@ static int intel_pstate_turbo_pstate(void)
 {
 	u64 value;
 	int nont, ret;
-	rdmsrl(0x1AD, value);
+	rdmsrl(MSR_NHM_TURBO_RATIO_LIMIT, value);
 	nont = intel_pstate_max_pstate();
 	ret = ((value) & 255);
 	if (ret <= nont)
@@ -454,7 +454,7 @@ static inline void intel_pstate_calc_busy(struct cpudata *cpu,
 					sample->idletime_us * 100,
 					sample->duration_us);
 	core_pct = div64_u64(sample->aperf * 100, sample->mperf);
-	sample->freq = cpu->pstate.turbo_pstate * core_pct * 1000;
+	sample->freq = cpu->pstate.max_pstate * core_pct * 1000;
 
 	sample->core_pct_busy = div_s64((sample->pstate_pct_busy * core_pct),
 					100);
@@ -752,6 +752,29 @@ static struct cpufreq_driver intel_pstate_driver = {
 
 static int __initdata no_load;
 
+static int intel_pstate_msrs_not_valid(void)
+{
+	/* Check that all the msr's we are using are valid. */
+	u64 aperf, mperf, tmp;
+
+	rdmsrl(MSR_IA32_APERF, aperf);
+	rdmsrl(MSR_IA32_MPERF, mperf);
+
+	if (!intel_pstate_min_pstate() ||
+		!intel_pstate_max_pstate() ||
+		!intel_pstate_turbo_pstate())
+		return -ENODEV;
+
+	rdmsrl(MSR_IA32_APERF, tmp);
+	if (!(tmp - aperf))
+		return -ENODEV;
+
+	rdmsrl(MSR_IA32_MPERF, tmp);
+	if (!(tmp - mperf))
+		return -ENODEV;
+
+	return 0;
+}
 static int __init intel_pstate_init(void)
 {
 	int cpu, rc = 0;
@@ -764,6 +787,9 @@ static int __init intel_pstate_init(void)
 	if (!id)
 		return -ENODEV;
 
+	if (intel_pstate_msrs_not_valid())
+		return -ENODEV;
+
 	pr_info("Intel P-state driver initializing.\n");
 
 	all_cpu_data = vmalloc(sizeof(void *) * num_possible_cpus());