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>
diff --git a/arch/avr32/mach-at32ap/cpufreq.c b/arch/avr32/mach-at32ap/cpufreq.c
index d84efe4..024c586 100644
--- a/arch/avr32/mach-at32ap/cpufreq.c
+++ b/arch/avr32/mach-at32ap/cpufreq.c
@@ -40,6 +40,9 @@
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 @@
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);
