[PATCH] hwmon: (w83l786ng) Clamp voltage limits before rounding

[Zhu Jun]

IN_TO_REG() adds 4 to an unrestricted unsigned long. Inputs close to
ULONG_MAX wrap, so an excessive voltage limit can select register zero
instead of 255.

Clamp to the 0..2040 mV register range before rounding to 8 mV units.

Fixes: 85f03bccd6e0 ("hwmon: Add support for Winbond W83L786NG/NR")
Signed-off-by: Zhu Jun <zhujun2@xxxxxxxxxxxxxxxxxxxx>
---
 drivers/hwmon/w83l786ng.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/hwmon/w83l786ng.c b/drivers/hwmon/w83l786ng.c
index d16afda34e41..0cd545011e73 100644
--- a/drivers/hwmon/w83l786ng.c
+++ b/drivers/hwmon/w83l786ng.c
@@ -101,7 +101,7 @@ static int temp_from_reg(int val)
  * in mV as would be measured on the chip input pin, need to just
  * multiply/divide by 8 to translate from/to register values.
  */
-#define IN_TO_REG(val)		(clamp_val((((val) + 4) / 8), 0, 255))
+#define IN_TO_REG(val)		((clamp_val((val), 0, 2040) + 4) / 8)
 #define IN_FROM_REG(val)	((val) * 8)
 
 #define DIV_FROM_REG(val)	(1 << (val))
-- 
2.51.0