[PATCH 4.9 30/36] thermal: exynos: Propagate error value from tmu_read()

[Greg Kroah-Hartman]

4.9-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Marek Szyprowski <m.szyprowski@xxxxxxxxxxx>

commit c8da6cdef57b459ac0fd5d9d348f8460a575ae90 upstream.

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@xxxxxxxxxxx>
CC: stable@xxxxxxxxxxxxxxx # v4.6+
Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@xxxxxxxxxxx>
Signed-off-by: Eduardo Valentin <edubezval@xxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 drivers/thermal/samsung/exynos_tmu.c |    9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

--- a/drivers/thermal/samsung/exynos_tmu.c
+++ b/drivers/thermal/samsung/exynos_tmu.c
@@ -892,6 +892,7 @@ static void exynos7_tmu_control(struct p
 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
 	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