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

[Viresh Kumar <viresh.kumar@linaro.org>]

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>

-- 
viresh