thermal: exynos: Propagate error value from tmu_read()

tmu_read() in case of Exynos4210 might return error for out of bound
values. Current code ignores such value, what leads to reporting critical
temperature value. Add proper error code propagation to exynos_get_temp()
function.

Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
CC: stable@vger.kernel.org # v4.6+
Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Signed-off-by: Eduardo Valentin <edubezval@gmail.com>

1 files changed, 7 insertions, 2 deletions

diff --git a/drivers/thermal/samsung/exynos_tmu.c b/drivers/thermal/samsung/exynos_tmu.c
index 986cbd01aaaa..ac83f721db24 100644
--- a/drivers/thermal/samsung/exynos_tmu.c
+++ b/drivers/thermal/samsung/exynos_tmu.c
@@ -892,6 +892,7 @@ static void exynos7_tmu_control(struct platform_device *pdev, bool on)
 static int exynos_get_temp(void *p, int *temp)
 {
         struct exynos_tmu_data *data = p;
+        int value, ret = 0;
 
         if (!data || !data->tmu_read || !data->enabled)
                 return -EINVAL;
@@ -899,12 +900,16 @@ static int exynos_get_temp(void *p, int *temp)
         mutex_lock(&data->lock);
         clk_enable(data->clk);
 
-        *temp = code_to_temp(data, data->tmu_read(data)) * MCELSIUS;
+        value = data->tmu_read(data);
+        if (value < 0)
+                ret = value;
+        else
+                *temp = code_to_temp(data, value) * MCELSIUS;
 
         clk_disable(data->clk);
         mutex_unlock(&data->lock);
 
-        return 0;
+        return ret;
 }
 
 #ifdef CONFIG_THERMAL_EMULATION