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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, Axel Lin <axel.lin@ingics.com>,
        Mark Brown <broonie@kernel.org>,
        Sasha Levin <sashal@kernel.org>
Subject: [PATCH 4.9 047/245] regulator: da9052: Ensure enough delay time for .set_voltage_time_sel
Date:   Mon, 19 Jul 2021 16:49:49 +0200
Message-Id: <20210719144941.921712782@linuxfoundation.org>
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From: Axel Lin <axel.lin@ingics.com>

[ Upstream commit a336dc8f683e5be794186b5643cd34cb28dd2c53 ]

Use DIV_ROUND_UP to prevent truncation by integer division issue.
This ensures we return enough delay time.

Also fix returning negative value when new_sel < old_sel.

Signed-off-by: Axel Lin <axel.lin@ingics.com>
Link: https://lore.kernel.org/r/20210618141412.4014912-1-axel.lin@ingics.com
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/regulator/da9052-regulator.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/regulator/da9052-regulator.c b/drivers/regulator/da9052-regulator.c
index 9ececfef42d6..bd91c95f73e0 100644
--- a/drivers/regulator/da9052-regulator.c
+++ b/drivers/regulator/da9052-regulator.c
@@ -258,7 +258,8 @@ static int da9052_regulator_set_voltage_time_sel(struct regulator_dev *rdev,
 	case DA9052_ID_BUCK3:
 	case DA9052_ID_LDO2:
 	case DA9052_ID_LDO3:
-		ret = (new_sel - old_sel) * info->step_uV / 6250;
+		ret = DIV_ROUND_UP(abs(new_sel - old_sel) * info->step_uV,
+				   6250);
 		break;
 	}
 
-- 
2.30.2