[PATCH v2 0/3] cpufreq/ondemand support for Xserve G5 & iMac G5 iSight

[PATCH v2 0/3] cpufreq/ondemand support for Xserve G5 & iMac G5 iSight

[Aaro Koskinen]

Hi,

This is a second version of the patch set sent earlier
(http://marc.info/?t=137461124900005&r=1&w=2) to enable ondemand on
Xserve G5, and also to enable cpufreq on the final iMac G5 (iSight) model.

I changed the second patch to so that it only adds the new latency value
for PowerMac7,2/PowerMac7,3/RackMac3,1.

The only other changes are ACKs from Viresh Kumar to patches 1 & 3.

A.

Aaro Koskinen (3):
  cpufreq: pmac64: speed up frequency switch
  cpufreq: pmac64: provide cpufreq transition latency for older G5
    models
  cpufreq: pmac64: enable cpufreq on iMac G5 (iSight) model

 drivers/cpufreq/pmac64-cpufreq.c | 13 ++++++++-----
 1 file changed, 8 insertions(+), 5 deletions(-)

-- 
1.8.3.2

[PATCH v2 1/3] cpufreq: pmac64: speed up frequency switch

[Aaro Koskinen]

Some functions on switch path use msleep() which is inaccurate, and
depends on HZ. With HZ=100 msleep(1) takes actually over ten times longer.
Using usleep_range() we get more accurate sleeps.

I measured the "pfunc_slewing_done" polling to take 300us at max (on
2.3GHz dual-processor Xserve G5), so using 500us sleep there should
be fine.

With the patch, g5_switch_freq() duration drops from ~50ms to ~10ms on
Xserve with HZ=100.

Signed-off-by: Aaro Koskinen <aaro.koskinen@iki.fi>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
---
 drivers/cpufreq/pmac64-cpufreq.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/cpufreq/pmac64-cpufreq.c b/drivers/cpufreq/pmac64-cpufreq.c
index 7ba4234..674807d 100644
--- a/drivers/cpufreq/pmac64-cpufreq.c
+++ b/drivers/cpufreq/pmac64-cpufreq.c
@@ -141,7 +141,7 @@ static void g5_vdnap_switch_volt(int speed_mode)
 		pmf_call_one(pfunc_vdnap0_complete, &args);
 		if (done)
 			break;
-		msleep(1);
+		usleep_range(1000, 1000);
 	}
 	if (done == 0)
 		printk(KERN_WARNING "cpufreq: Timeout in clock slewing !\n");
@@ -240,7 +240,7 @@ static void g5_pfunc_switch_volt(int speed_mode)
 		if (pfunc_cpu1_volt_low)
 			pmf_call_one(pfunc_cpu1_volt_low, NULL);
 	}
-	msleep(10); /* should be faster , to fix */
+	usleep_range(10000, 10000); /* should be faster , to fix */
 }
 
 /*
@@ -285,7 +285,7 @@ static int g5_pfunc_switch_freq(int speed_mode)
 		pmf_call_one(pfunc_slewing_done, &args);
 		if (done)
 			break;
-		msleep(1);
+		usleep_range(500, 500);
 	}
 	if (done == 0)
 		printk(KERN_WARNING "cpufreq: Timeout in clock slewing !\n");
-- 
1.8.3.2

[PATCH v2 2/3] cpufreq: pmac64: provide cpufreq transition latency for older G5 models

[Aaro Koskinen]

Currently cpufreq ondemand governor cannot used on older G5 models,
because the transition latency is set to CPUFREQ_ETERNAL. Provide a
value based on a measurement on Xserve G5, which happens to be also the
highest allowed latency.

Signed-off-by: Aaro Koskinen <aaro.koskinen@iki.fi>
---
 drivers/cpufreq/pmac64-cpufreq.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/cpufreq/pmac64-cpufreq.c b/drivers/cpufreq/pmac64-cpufreq.c
index 674807d..d3d1995 100644
--- a/drivers/cpufreq/pmac64-cpufreq.c
+++ b/drivers/cpufreq/pmac64-cpufreq.c
@@ -674,8 +674,10 @@ static int __init g5_pm72_cpufreq_init(struct device_node *cpus)
 	g5_cpu_freqs[0].frequency = max_freq;
 	g5_cpu_freqs[1].frequency = min_freq;
 
+	/* Based on a measurement on Xserve G5, rounded up. */
+	transition_latency = 10 * NSEC_PER_MSEC;
+
 	/* 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

[PATCH v2 3/3] cpufreq: pmac64: enable cpufreq on iMac G5 (iSight) model

[Aaro Koskinen]

Enable cpufreq on iMac G5 (iSight) model. Tested with the 2.1 GHz version.

Signed-off-by: Aaro Koskinen <aaro.koskinen@iki.fi>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
---
 drivers/cpufreq/pmac64-cpufreq.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/cpufreq/pmac64-cpufreq.c b/drivers/cpufreq/pmac64-cpufreq.c
index d3d1995..699e0a5 100644
--- a/drivers/cpufreq/pmac64-cpufreq.c
+++ b/drivers/cpufreq/pmac64-cpufreq.c
@@ -398,7 +398,8 @@ static int __init g5_neo2_cpufreq_init(struct device_node *cpus)
 	/* Check supported platforms */
 	if (of_machine_is_compatible("PowerMac8,1") ||
 	    of_machine_is_compatible("PowerMac8,2") ||
-	    of_machine_is_compatible("PowerMac9,1"))
+	    of_machine_is_compatible("PowerMac9,1") ||
+	    of_machine_is_compatible("PowerMac12,1"))
 		use_volts_smu = 1;
 	else if (of_machine_is_compatible("PowerMac11,2"))
 		use_volts_vdnap = 1;
-- 
1.8.3.2