On Thu, Feb 25, 2016 at 12:30:43AM +0100, Rafael J. Wysocki wrote:
> +unsigned int acpi_cpufreq_fast_switch(struct cpufreq_policy *policy,
> + unsigned int target_freq)
> +{
> + struct acpi_cpufreq_data *data = policy->driver_data;
> + struct cpufreq_frequency_table *entry;
> + struct acpi_processor_performance *perf;
> + unsigned int uninitialized_var(next_perf_state);
> + unsigned int uninitialized_var(next_freq);
> + unsigned int best_diff;
> +
> + for (entry = data->freq_table, best_diff = UINT_MAX;
> + entry->frequency != CPUFREQ_TABLE_END; entry++) {
> + unsigned int diff, freq = entry->frequency;
> +
> + if (freq == CPUFREQ_ENTRY_INVALID)
> + continue;
> +
> + diff = abs(freq - target_freq);
Why would you consider frequencies that are below where you want to be?
> + if (diff >= best_diff)
> + continue;
> +
> + best_diff = diff;
> + next_perf_state = entry->driver_data;
> + next_freq = freq;
> + if (best_diff == 0)
> + goto found;
> + }
> + if (best_diff == UINT_MAX)
> + return CPUFREQ_ENTRY_INVALID;
> +
> + found:
> + perf = to_perf_data(data);
> + if (perf->state == next_perf_state) {
> + if (unlikely(data->resume))
> + data->resume = 0;
> + else
> + return next_freq;
> + }
> +
> + data->cpu_freq_fast_write(perf->states[next_perf_state].control);
> + perf->state = next_perf_state;
> + return next_freq;
> +}
