From 40be4c3ccbf4078e2f8426a7962879b7a447cde4 Mon Sep 17 00:00:00 2001 From: Pi-Cheng Chen Date: Sun, 29 Nov 2015 16:31:37 +0800 Subject: [PATCH] cpufreq: mt8173: check return value of regulator_get_voltage() call 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 Acked-by: Viresh Kumar Signed-off-by: Rafael J. Wysocki --- 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 750cda7876ac..9d0fe37b4c3e 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; -- 2.39.5