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authorAndreas Schwab <schwab@linux-m68k.org>2012-10-28 23:15:14 +0000
committerBenjamin Herrenschmidt <benh@kernel.crashing.org>2012-11-15 13:00:33 +1100
commitbb29b719372742939af05457aff1b59608764e89 (patch)
tree2132db6166f40da511fb0e04119799a568345270 /arch/powerpc/platforms/powermac
parentec1b33dcd2c0ed773e6458d1c8b337966114562b (diff)
downloadblackbird-op-linux-bb29b719372742939af05457aff1b59608764e89.tar.gz
blackbird-op-linux-bb29b719372742939af05457aff1b59608764e89.zip
powerpc/powermac/cpufreq_32: Set non-infinite transition time for 7447A driver
The transition time for the 7447A is around 8ms which makes it possible to use the ondemand governor. This has been tested on the iBook G4 (PowerBook6,7). Signed-off-by: Andreas Schwab <schwab@linux-m68k.org> Tested-by: Michel Dänzer <michel@daenzer.net> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Diffstat (limited to 'arch/powerpc/platforms/powermac')
-rw-r--r--arch/powerpc/platforms/powermac/cpufreq_32.c5
1 files changed, 4 insertions, 1 deletions
diff --git a/arch/powerpc/platforms/powermac/cpufreq_32.c b/arch/powerpc/platforms/powermac/cpufreq_32.c
index 64171198535c..311b804353b1 100644
--- a/arch/powerpc/platforms/powermac/cpufreq_32.c
+++ b/arch/powerpc/platforms/powermac/cpufreq_32.c
@@ -55,6 +55,7 @@ static unsigned int low_freq;
static unsigned int hi_freq;
static unsigned int cur_freq;
static unsigned int sleep_freq;
+static unsigned long transition_latency;
/*
* Different models uses different mechanisms to switch the frequency
@@ -403,7 +404,7 @@ static int pmac_cpufreq_cpu_init(struct cpufreq_policy *policy)
if (policy->cpu != 0)
return -ENODEV;
- policy->cpuinfo.transition_latency = CPUFREQ_ETERNAL;
+ policy->cpuinfo.transition_latency = transition_latency;
policy->cur = cur_freq;
cpufreq_frequency_table_get_attr(pmac_cpu_freqs, policy->cpu);
@@ -658,12 +659,14 @@ static int __init pmac_cpufreq_setup(void)
if (!value)
goto out;
cur_freq = (*value) / 1000;
+ transition_latency = CPUFREQ_ETERNAL;
/* Check for 7447A based MacRISC3 */
if (of_machine_is_compatible("MacRISC3") &&
of_get_property(cpunode, "dynamic-power-step", NULL) &&
PVR_VER(mfspr(SPRN_PVR)) == 0x8003) {
pmac_cpufreq_init_7447A(cpunode);
+ transition_latency = 8000000;
/* Check for other MacRISC3 machines */
} else if (of_machine_is_compatible("PowerBook3,4") ||
of_machine_is_compatible("PowerBook3,5") ||
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