linux-kernel - [PATCH V2 12/15] cpufreq: mediatek: Use maximum voltage in init stage

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20220408045908.21671-13-rex-bc.chen@mediatek.com>
Date:   Fri, 8 Apr 2022 12:59:05 +0800
From:   Rex-BC Chen <rex-bc.chen@...iatek.com>
To:     <rafael@...nel.org>, <viresh.kumar@...aro.org>,
        <robh+dt@...nel.org>, <krzk+dt@...nel.org>
CC:     <matthias.bgg@...il.com>, <jia-wei.chang@...iatek.com>,
        <roger.lu@...iatek.com>, <hsinyi@...gle.com>,
        <linux-pm@...r.kernel.org>, <devicetree@...r.kernel.org>,
        <linux-kernel@...r.kernel.org>,
        <linux-arm-kernel@...ts.infradead.org>,
        <linux-mediatek@...ts.infradead.org>,
        <Project_Global_Chrome_Upstream_Group@...iatek.com>
Subject: [PATCH V2 12/15] cpufreq: mediatek: Use maximum voltage in init stage

From: Jia-Wei Chang <jia-wei.chang@...iatek.com>

Two or more clients may use the same regulator, and it could cause the
issue of high-freqeuncy-low-voltage.
To prevent this, we use maximum voltage in mtk_cpu_dvfs_info_init().

Signed-off-by: Jia-Wei Chang <jia-wei.chang@...iatek.com>
---
 drivers/cpufreq/mediatek-cpufreq.c | 20 +++++++++++++++++++-
 1 file changed, 19 insertions(+), 1 deletion(-)

diff --git a/drivers/cpufreq/mediatek-cpufreq.c b/drivers/cpufreq/mediatek-cpufreq.c
index e69b16a6541e..b08ab7c14818 100644
--- a/drivers/cpufreq/mediatek-cpufreq.c
+++ b/drivers/cpufreq/mediatek-cpufreq.c
@@ -333,7 +333,7 @@ static int mtk_cpu_dvfs_info_init(struct mtk_cpu_dvfs_info *info, int cpu)
 {
 	struct device *cpu_dev;
 	struct dev_pm_opp *opp;
-	unsigned long rate;
+	unsigned long rate, opp_volt;
 	int ret;
 
 	cpu_dev = get_cpu_device(cpu);
@@ -417,6 +417,24 @@ static int mtk_cpu_dvfs_info_init(struct mtk_cpu_dvfs_info *info, int cpu)
 	info->intermediate_voltage = dev_pm_opp_get_voltage(opp);
 	dev_pm_opp_put(opp);
 
+	/* Use highest opp voltage in the init stage */
+	rate = U32_MAX;
+	opp = dev_pm_opp_find_freq_floor(info->cpu_dev, &rate);
+	if (IS_ERR(opp)) {
+		ret = PTR_ERR(opp);
+		dev_err(cpu_dev, "cpu%d: failed to get opp\n", info->opp_cpu);
+		goto out_disable_inter_clock;
+	}
+
+	opp_volt = dev_pm_opp_get_voltage(opp);
+	dev_pm_opp_put(opp);
+	ret = mtk_cpufreq_set_voltage(info, opp_volt);
+	if (ret) {
+		dev_err(cpu_dev, "cpu%d: failed to scale to highest voltage %lu in proc_reg\n",
+			info->opp_cpu, opp_volt);
+		goto out_disable_inter_clock;
+	}
+
 	info->opp_cpu = cpu;
 	info->opp_nb.notifier_call = mtk_cpufreq_opp_notifier;
 	ret = dev_pm_opp_register_notifier(cpu_dev, &info->opp_nb);
-- 
2.18.0