[PATCH 2/3] cpufreq: pmac64: re-estimate G5 cpufreq transition latency

[Aaro Koskinen]

The latency is in milliseconds scale rather than microseconds based on
measurements on iMac G5 and Xscale G5. The patch also enables to use
ondemand governor on the latter.

Signed-off-by: Aaro Koskinen <aaro.koskinen at iki.fi>
---
 drivers/cpufreq/pmac64-cpufreq.c | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/drivers/cpufreq/pmac64-cpufreq.c b/drivers/cpufreq/pmac64-cpufreq.c
index 674807d..f9e399b 100644
--- a/drivers/cpufreq/pmac64-cpufreq.c
+++ b/drivers/cpufreq/pmac64-cpufreq.c
@@ -85,7 +85,8 @@ static int (*g5_query_freq)(void);
 
 static DEFINE_MUTEX(g5_switch_mutex);
 
-static unsigned long transition_latency;
+/* A conservative estimate, based on Xserve G5 and iMac G5 (iSight). */
+static const unsigned long transition_latency = 10 * NSEC_PER_MSEC;
 
 #ifdef CONFIG_PMAC_SMU
 
@@ -499,7 +500,6 @@ static int __init g5_neo2_cpufreq_init(struct device_node *cpus)
 	g5_cpu_freqs[1].frequency = max_freq/2;
 
 	/* Set callbacks */
-	transition_latency = 12000;
 	g5_switch_freq = g5_scom_switch_freq;
 	g5_query_freq = g5_scom_query_freq;
 	freq_method = "SCOM";
@@ -675,7 +675,6 @@ static int __init g5_pm72_cpufreq_init(struct device_node *cpus)
 	g5_cpu_freqs[1].frequency = min_freq;
 
 	/* Set callbacks */
-	transition_latency = CPUFREQ_ETERNAL;
 	g5_switch_volt = g5_pfunc_switch_volt;
 	g5_switch_freq = g5_pfunc_switch_freq;
 	g5_query_freq = g5_pfunc_query_freq;
-- 
1.8.3.2