Hi Lukasz,

[..]

quoted

+
+/* Obtain max frequency (in KHz) as reported by hardware */
+__weak unsigned int cpu_get_max_freq(unsigned int cpu)
+{
+	return 0;
+}
+
+#ifdef CONFIG_CPU_FREQ
+/* Replace max frequency getter with cpufreq based function */
+#define cpu_get_max_freq cpufreq_get_hw_max_freq
+#endif

Can we just use cpufreq_get_hw_max_freq()?
We have cpufreq_get_hw_max_freq returning 0 in such case, so it should
be OK.

The reasoning for the implementation is the following:
 - For CONFIG_CPU_FREQ we use cpufreq_get_hw_max_freq (weak default or
   strong alternative)
 - For !CONFIG_CPU_FREQ cpufreq_get_hw_max_freq returns 0 - it signals
   that cpufreq cannot return the hardware max frequency. In this case
   cpu_get_max_freq is used (weak default or strong alternative
   implementation).

Is there a possibility that some platform which has !CONFIG_CPU_FREQ
would define its own cpu_get_max_freq() overwriting the weak function
above?
Based on the code which checks 'if (unlikely(!max_freq_hz))' it should,
otherwise 'valid_cpus' is not set.

I would assume that we won't see such platform, interested
in AMU freq invariance without CONFIG_CPU_FREQ.

We already have a lot of these defines or __weak functions, which is
hard to follow.

There is no dependency between CONFIG_CPU_FREQ and frequency invariance.
Therefore, I did not see a reason to potentially bypass the use of AMU
for frequency invariance for !CONFIG_CPU_FREQ.

But I agree it makes the code harder to read so I can remove
cpu_get_max_freq and keep cpufreq_get_hw_max_freq only until there is a
provable need for this. 

Thank you for the review,
Ionela.

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