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From:   Sasha Levin <Alexander.Levin@microsoft.com>
To:     "stable@vger.kernel.org" <stable@vger.kernel.org>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
CC:     Jean-Christophe Dubois <jcd@tribudubois.net>,
        Eduardo Valentin <edubezval@gmail.com>,
        Sasha Levin <Alexander.Levin@microsoft.com>
Subject: [PATCH AUTOSEL 4.18 048/136] thermal: i.MX: Allow thermal probe to
 fail gracefully in case of bad calibration.
Thread-Topic: [PATCH AUTOSEL 4.18 048/136] thermal: i.MX: Allow thermal probe
 to fail gracefully in case of bad calibration.
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Date:   Mon, 17 Sep 2018 03:00:42 +0000
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From: Jean-Christophe Dubois <jcd@tribudubois.net>

[ Upstream commit be926ceeb4efc3bf44cb9b56f5c71aac9b1f8bbe ]

Without this fix, the thermal probe on i.MX6 might trigger a division
by zero exception later in the probe if the calibration does fail.

Note: This linux behavior (Division by zero in kernel) has been triggered
on a Qemu i.MX6 emulation where parameters in nvmem were not set. With this
fix the division by zero is not triggeed anymore as the thermal probe does
fail early.

Signed-off-by: Jean-Christophe Dubois <jcd@tribudubois.net>
Reviewed-by: Fabio Estevam <fabio.estevam@nxp.com>
Signed-off-by: Eduardo Valentin <edubezval@gmail.com>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
---
 drivers/thermal/imx_thermal.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/thermal/imx_thermal.c b/drivers/thermal/imx_thermal.c
index 334d98be03b9..b1f82d64253e 100644
--- a/drivers/thermal/imx_thermal.c
+++ b/drivers/thermal/imx_thermal.c
@@ -604,7 +604,10 @@ static int imx_init_from_nvmem_cells(struct platform_d=
evice *pdev)
 	ret =3D nvmem_cell_read_u32(&pdev->dev, "calib", &val);
 	if (ret)
 		return ret;
-	imx_init_calib(pdev, val);
+
+	ret =3D imx_init_calib(pdev, val);
+	if (ret)
+		return ret;
=20
 	ret =3D nvmem_cell_read_u32(&pdev->dev, "temp_grade", &val);
 	if (ret)
--=20
2.17.1