linux-kernel - [PATCH 5.15 105/177] cpufreq: qcom-cpufreq-hw: Clear dcvs interrupts

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Date:   Wed,  4 May 2022 18:44:58 +0200
From:   Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To:     linux-kernel@...r.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        stable@...r.kernel.org,
        Vladimir Zapolskiy <vladimir.zapolskiy@...aro.org>,
        Viresh Kumar <viresh.kumar@...aro.org>,
        Sasha Levin <sashal@...nel.org>
Subject: [PATCH 5.15 105/177] cpufreq: qcom-cpufreq-hw: Clear dcvs interrupts

From: Vladimir Zapolskiy <vladimir.zapolskiy@...aro.org>

[ Upstream commit e4e6448638a01905faeda9bf96aa9df7c8ef463c ]

It's noted that dcvs interrupts are not self-clearing, thus an interrupt
handler runs constantly, which leads to a severe regression in runtime.
To fix the problem an explicit write to clear interrupt register is
required, note that on OSM platforms the register may not be present.

Fixes: 275157b367f4 ("cpufreq: qcom-cpufreq-hw: Add dcvs interrupt support")
Signed-off-by: Vladimir Zapolskiy <vladimir.zapolskiy@...aro.org>
Signed-off-by: Viresh Kumar <viresh.kumar@...aro.org>
Signed-off-by: Sasha Levin <sashal@...nel.org>
---
 drivers/cpufreq/qcom-cpufreq-hw.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/drivers/cpufreq/qcom-cpufreq-hw.c b/drivers/cpufreq/qcom-cpufreq-hw.c
index e73ecab23c85..bb2f59fd0de4 100644
--- a/drivers/cpufreq/qcom-cpufreq-hw.c
+++ b/drivers/cpufreq/qcom-cpufreq-hw.c
@@ -24,6 +24,8 @@
 #define CLK_HW_DIV			2
 #define LUT_TURBO_IND			1
 
+#define GT_IRQ_STATUS			BIT(2)
+
 #define HZ_PER_KHZ			1000
 
 struct qcom_cpufreq_soc_data {
@@ -31,6 +33,7 @@ struct qcom_cpufreq_soc_data {
 	u32 reg_domain_state;
 	u32 reg_freq_lut;
 	u32 reg_volt_lut;
+	u32 reg_intr_clr;
 	u32 reg_current_vote;
 	u32 reg_perf_state;
 	u8 lut_row_size;
@@ -349,6 +352,10 @@ static irqreturn_t qcom_lmh_dcvs_handle_irq(int irq, void *data)
 	disable_irq_nosync(c_data->throttle_irq);
 	schedule_delayed_work(&c_data->throttle_work, 0);
 
+	if (c_data->soc_data->reg_intr_clr)
+		writel_relaxed(GT_IRQ_STATUS,
+			       c_data->base + c_data->soc_data->reg_intr_clr);
+
 	return IRQ_HANDLED;
 }
 
@@ -366,6 +373,7 @@ static const struct qcom_cpufreq_soc_data epss_soc_data = {
 	.reg_domain_state = 0x20,
 	.reg_freq_lut = 0x100,
 	.reg_volt_lut = 0x200,
+	.reg_intr_clr = 0x308,
 	.reg_perf_state = 0x320,
 	.lut_row_size = 4,
 };
-- 
2.35.1