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

Message ID 1448785898-17838-3-git-send-email-pi-cheng.chen@linaro.org
State New
Headers show

Commit Message

pi-cheng.chen Nov. 29, 2015, 8:31 a.m.
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(+)

-- 
1.9.1

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Comments

Viresh Kumar Nov. 30, 2015, 5:27 a.m. | #1
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
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Patch

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;