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powerpc/powermac/cpufreq_32: Set non-infinite transition time for 7447A driver

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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>
This commit is contained in:
Andreas Schwab 2012-10-28 23:15:14 +00:00 committed by Benjamin Herrenschmidt
parent ec1b33dcd2
commit bb29b71937
1 changed files with 4 additions and 1 deletions
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5
arch/powerpc/platforms/powermac/cpufreq_32.c
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@ -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") ||