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avr32: Scale loops_per_jiffy when cpu frequency changes 

The loops_per_jiffy variable isn't updated when cpufreq changes the CPU
frequency. This could cause udelay() and friends to produce wrong
delays.

Signed-off-by: Haavard Skinnemoen <haavard.skinnemoen@atmel.com>
This commit is contained in:
Haavard Skinnemoen 2008-10-23 11:23:08 +02:00
parent 6090065663
commit e3f91ca481
1 changed files with 14 additions and 0 deletions
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14
arch/avr32/mach-at32ap/cpufreq.c
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@ -40,6 +40,9 @@ static unsigned int at32_get_speed(unsigned int cpu)
return (unsigned int)((clk_get_rate(cpuclk) + 500) / 1000);
}
static unsigned int ref_freq;
static unsigned long loops_per_jiffy_ref;
static int at32_set_target(struct cpufreq_policy *policy,
unsigned int target_freq,
unsigned int relation)
@ -61,8 +64,19 @@ static int at32_set_target(struct cpufreq_policy *policy,
freqs.cpu = 0;
freqs.flags = 0;
if (!ref_freq) {
ref_freq = freqs.old;
loops_per_jiffy_ref = boot_cpu_data.loops_per_jiffy;
}
cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE);
if (freqs.old < freqs.new)
boot_cpu_data.loops_per_jiffy = cpufreq_scale(
loops_per_jiffy_ref, ref_freq, freqs.new);
clk_set_rate(cpuclk, freq);
if (freqs.new < freqs.old)
boot_cpu_data.loops_per_jiffy = cpufreq_scale(
loops_per_jiffy_ref, ref_freq, freqs.new);
cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE);
pr_debug("cpufreq: set frequency %lu Hz\n", freq);