thermal: i.MX: Allow thermal probe to fail gracefully in case of bad calibration.

BugLink: https://bugs.launchpad.net/bugs/1836287
[ 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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>
Signed-off-by: Khalid Elmously <khalid.elmously@canonical.com>

diff --git a/drivers/thermal/imx_thermal.c b/drivers/thermal/imx_thermal.c
index 5664820b437c0ac03b52bad2092a76fc461db44b..4347653f46ceda8f63ddba613ce2fb3943a703ec 100644 (file)
--- a/drivers/thermal/imx_thermal.c
+++ b/drivers/thermal/imx_thermal.c
@@ -465,7 +465,10 @@ static int imx_init_from_nvmem_cells(struct platform_device *pdev)
        ret = nvmem_cell_read_u32(&pdev->dev, "calib", &val);
        if (ret)
                return ret;
-       imx_init_calib(pdev, val);
+
+       ret = imx_init_calib(pdev, val);
+       if (ret)
+               return ret;
 
        ret = nvmem_cell_read_u32(&pdev->dev, "temp_grade", &val);
        if (ret)