Re: [PATCH 3/4] cpufreq: mt8173: check return value of regulator_get_voltage() call

Viresh Kumar
2015-11-30T05:28:18Z

On 29-11-15, 16:31, Pi-Cheng Chen wrote:
> Sometimes regulator_get_voltage() call returns negative values for
> reasons(e.g. underlying I2C bus timeout). Add check for the return
> values and fail out early.
>
> Signed-off-by: Pi-Cheng Chen <pi-cheng.chen@linaro.org>
> ---
> drivers/cpufreq/mt8173-cpufreq.c | 28 ++++++++++++++++++++++++++++
> 1 file changed, 28 insertions(+)
>
> diff --git a/drivers/cpufreq/mt8173-cpufreq.c b/drivers/cpufreq/mt8173-cpufreq.c
> index 750cda7..9d0fe37 100644
> --- a/drivers/cpufreq/mt8173-cpufreq.c
> +++ b/drivers/cpufreq/mt8173-cpufreq.c
> @@ -59,6 +59,10 @@ static int mtk_cpufreq_voltage_tracking(struct mtk_cpu_dvfs_info *info,
> int old_vproc, old_vsram, new_vsram, vsram, vproc, ret;
>
> old_vproc = regulator_get_voltage(proc_reg);
> + if (old_vproc < 0) {
> + pr_err("%s: invalid Vproc value: %d\n", __func__, old_vproc);
> + return old_vproc;
> + }
> /* Vsram should not exceed the maximum allowed voltage of SoC. */
> new_vsram = min(new_vproc + MIN_VOLT_SHIFT, MAX_VOLT_LIMIT);
>
> @@ -71,7 +75,17 @@ static int mtk_cpufreq_voltage_tracking(struct mtk_cpu_dvfs_info *info,
> */
> do {
> old_vsram = regulator_get_voltage(sram_reg);
> + if (old_vsram < 0) {
> + pr_err("%s: invalid Vsram value: %d\n",
> + __func__, old_vsram);
> + return old_vsram;
> + }
> old_vproc = regulator_get_voltage(proc_reg);
> + if (old_vproc < 0) {
> + pr_err("%s: invalid Vproc value: %d\n",
> + __func__, old_vproc);
> + return old_vproc;
> + }
>
> vsram = min(new_vsram, old_vproc + MAX_VOLT_SHIFT);
>
> @@ -116,7 +130,17 @@ static int mtk_cpufreq_voltage_tracking(struct mtk_cpu_dvfs_info *info,
> */
> do {
> old_vproc = regulator_get_voltage(proc_reg);
> + if (old_vproc < 0) {
> + pr_err("%s: invalid Vproc value: %d\n",
> + __func__, old_vproc);
> + return old_vproc;
> + }
> old_vsram = regulator_get_voltage(sram_reg);
> + if (old_vsram < 0) {
> + pr_err("%s: invalid Vsram value: %d\n",
> + __func__, old_vsram);
> + return old_vsram;
> + }
>
> vproc = max(new_vproc, old_vsram - MAX_VOLT_SHIFT);
> ret = regulator_set_voltage(proc_reg, vproc,
> @@ -184,6 +208,10 @@ static int mtk_cpufreq_set_target(struct cpufreq_policy *policy,
>
> old_freq_hz = clk_get_rate(cpu_clk);
> old_vproc = regulator_get_voltage(info->proc_reg);
> + if (old_vproc < 0) {
> + pr_err("%s: invalid Vproc value: %d\n", __func__, old_vproc);
> + return old_vproc;
> + }
>
> freq_hz = freq_table[index].frequency * 1000;

Acked-by: Viresh Kumar <viresh.kumar@linaro.org>

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viresh