Re: [PATCH 1/1] cpufreq: cpufreq-cpu0: use the max voltage instead of voltage-tolerance
From: Viresh Kumar
Date: Mon Nov 04 2013 - 23:38:17 EST
Adding shawn in cc list..
On 5 November 2013 08:40, rjying <rjying@xxxxxxxxx> wrote:
> From: Rongjun Ying <rongjun.ying@xxxxxxx>
>
> Sometime the regulator can't supply appropriate voltages for requestion of cpu.
> All voltage tolerance value can't figure out a good voltage.
>
> Signed-off-by: Rongjun Ying <rongjun.ying@xxxxxxx>
> ---
> drivers/cpufreq/cpufreq-cpu0.c | 17 ++++++++++-------
> 1 files changed, 10 insertions(+), 7 deletions(-)
>
> diff --git a/drivers/cpufreq/cpufreq-cpu0.c b/drivers/cpufreq/cpufreq-cpu0.c
> index c522a95..0c9e6b9 100644
> --- a/drivers/cpufreq/cpufreq-cpu0.c
> +++ b/drivers/cpufreq/cpufreq-cpu0.c
> @@ -23,7 +23,7 @@
> #include <linux/slab.h>
>
> static unsigned int transition_latency;
> -static unsigned int voltage_tolerance; /* in percentage */
> +static unsigned int voltage_max;
>
> static struct device *cpu_dev;
> static struct clk *cpu_clk;
> @@ -45,7 +45,7 @@ static int cpu0_set_target(struct cpufreq_policy *policy,
> {
> struct cpufreq_freqs freqs;
> struct opp *opp;
> - unsigned long volt = 0, volt_old = 0, tol = 0;
> + unsigned long volt = 0, volt_old = 0;
> long freq_Hz, freq_exact;
> unsigned int index;
> int ret;
> @@ -82,7 +82,6 @@ static int cpu0_set_target(struct cpufreq_policy *policy,
> }
> volt = opp_get_voltage(opp);
> rcu_read_unlock();
> - tol = volt * voltage_tolerance / 100;
> volt_old = regulator_get_voltage(cpu_reg);
> }
>
> @@ -92,7 +91,7 @@ static int cpu0_set_target(struct cpufreq_policy *policy,
>
> /* scaling up? scale voltage before frequency */
> if (!IS_ERR(cpu_reg) && freqs.new > freqs.old) {
> - ret = regulator_set_voltage_tol(cpu_reg, volt, tol);
> + ret = regulator_set_voltage(cpu_reg, volt, voltage_max);
> if (ret) {
> pr_err("failed to scale voltage up: %d\n", ret);
> freqs.new = freqs.old;
> @@ -104,14 +103,14 @@ static int cpu0_set_target(struct cpufreq_policy *policy,
> if (ret) {
> pr_err("failed to set clock rate: %d\n", ret);
> if (!IS_ERR(cpu_reg))
> - regulator_set_voltage_tol(cpu_reg, volt_old, tol);
> + regulator_set_voltage(cpu_reg, volt_old, voltage_max);
> freqs.new = freqs.old;
> goto post_notify;
> }
>
> /* scaling down? scale voltage after frequency */
> if (!IS_ERR(cpu_reg) && freqs.new < freqs.old) {
> - ret = regulator_set_voltage_tol(cpu_reg, volt, tol);
> + ret = regulator_set_voltage(cpu_reg, volt, voltage_max);
> if (ret) {
> pr_err("failed to scale voltage down: %d\n", ret);
> clk_set_rate(cpu_clk, freqs.old * 1000);
> @@ -224,7 +223,11 @@ static int cpu0_cpufreq_probe(struct platform_device *pdev)
> goto out_put_node;
> }
>
> - of_property_read_u32(np, "voltage-tolerance", &voltage_tolerance);
> + ret = of_property_read_u32(np, "voltage-max", &voltage_max);
> + if (ret) {
> + pr_err("failed to get max voltage: %d\n", ret);
> + goto out_put_node;
> + }
>
> if (of_property_read_u32(np, "clock-latency", &transition_latency))
> transition_latency = CPUFREQ_ETERNAL;
> --
> 1.7.5.4
>
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