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From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org, Zeal Robot <zealci@zte.com.cn>,
        Changcheng Deng <deng.changcheng@zte.com.cn>,
        Bjorn Andersson <bjorn.andersson@linaro.org>,
        Sasha Levin <sashal@kernel.org>
Subject: [PATCH 5.15 574/846] PM: AVS: qcom-cpr: Use div64_ul instead of do_div
Date:   Mon, 24 Jan 2022 19:41:31 +0100
Message-Id: <20220124184120.836060659@linuxfoundation.org>
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From: Changcheng Deng <deng.changcheng@zte.com.cn>

[ Upstream commit 92c550f9ffd2884bb5def52b5c0485a35e452784 ]

do_div() does a 64-by-32 division. Here the divisor is an unsigned long
which on some platforms is 64 bit wide. So use div64_ul instead of do_div
to avoid a possible truncation.

Reported-by: Zeal Robot <zealci@zte.com.cn>
Signed-off-by: Changcheng Deng <deng.changcheng@zte.com.cn>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Link: https://lore.kernel.org/r/20211125014311.45942-1-deng.changcheng@zte.com.cn
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/soc/qcom/cpr.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/soc/qcom/cpr.c b/drivers/soc/qcom/cpr.c
index 4ce8e816154f9..84dd93472a252 100644
--- a/drivers/soc/qcom/cpr.c
+++ b/drivers/soc/qcom/cpr.c
@@ -1010,7 +1010,7 @@ static int cpr_interpolate(const struct corner *corner, int step_volt,
 		return corner->uV;
 
 	temp = f_diff * (uV_high - uV_low);
-	do_div(temp, f_high - f_low);
+	temp = div64_ul(temp, f_high - f_low);
 
 	/*
 	 * max_volt_scale has units of uV/MHz while freq values
-- 
2.34.1