Hi Thomas, Please see my comments inline. On 09.01.2014 16:59, Thomas Abraham wrote: [snip]
@@ -69,12 +71,26 @@ static int cpu0_set_target(struct cpufreq_policy *policy, unsigned int index) new_freq / 1000, volt ? volt / 1000 : -1); /* scaling up? scale voltage before frequency */ - if (!IS_ERR(cpu_reg) && new_freq > old_freq) { + if (!IS_ERR(cpu_reg) && new_freq > old_freq && + new_freq >= safe_frequency) { ret = regulator_set_voltage_tol(cpu_reg, volt, tol); if (ret) { pr_err("failed to scale voltage up: %d\n", ret); return ret; } + } else if (!IS_ERR(cpu_reg) && old_freq < safe_frequency) { + /* + * the scaled up voltage level for the new_freq is lower + * than the safe voltage level. so set safe_voltage + * as the intermediate voltage level and revert it + * back after the frequency has been changed. + */ + ret = regulator_set_voltage(cpu_reg, safe_voltage, + safe_voltage);
Shouldn't the tolerance be used here as well?
+ if (ret) { + pr_err("failed to set safe voltage: %d\n", ret); + return ret; + } } ret = clk_set_rate(cpu_clk, freq_exact); @@ -94,6 +110,19 @@ static int cpu0_set_target(struct cpufreq_policy *policy, unsigned int index) } } + /* + * if safe voltage was applied during voltage scale up, then set + * the correct target voltage now. + */ + if (!IS_ERR(cpu_reg) && new_freq > old_freq && + new_freq < safe_frequency) { + ret = regulator_set_voltage_tol(cpu_reg, volt, tol); + if (ret) { + pr_err("failed to scale voltage up: %d\n", ret); + return ret; + } + } +
I believe that it would be enough to reuse the if block of scaling down instead of repeating the same code, just the condition must be slightly modified:
- /* scaling down? scale voltage after frequency */ - if (!IS_ERR(cpu_reg) && new_freq < old_freq) { + /* + * scaling down or below safe frequency? + * scale voltage after frequency + */ + if (!IS_ERR(cpu_reg) + && (new_freq < old_freq || new_freq < safe_frequency)) { Best regards, Tomasz -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html