From ccef20232ded30ca6e73865458ebe89c0fe48dfe Mon Sep 17 00:00:00 2001
From: Markus Stockhausen <markus.stockhausen@gmx.de>
Date: Sat, 2 May 2026 19:32:07 +0200
Subject: hwmon: (lm75) Fix configuration register writes.

Sensors configurations are defined by set and clear masks. These
do not follow a consistent "clear mask is a superset of set mask"
rule. This relaxed definition breaks lm75_write_config()

static inline int lm75_write_config(struct lm75_data *data, u16 set_mask,
				    u16 clr_mask)
{
	return regmap_update_bits(data->regmap, LM75_REG_CONF,
				  clr_mask | LM75_SHUTDOWN, set_mask);
}

Basically all bits from set_mask that are not defined in clr_mask are
dropped. Fix that by enhancing the helper to always combine clr_mask
and set_mask into the mask bits of regmap_update_bits().

Fixes: 6da24a25f766 ("hwmon: (lm75) Hide register size differences in regmap access functions")
Suggested-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Markus Stockhausen <markus.stockhausen@gmx.de>
Link: https://lore.kernel.org/r/20260502173207.3567876-3-markus.stockhausen@gmx.de
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
---
 drivers/hwmon/lm75.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/drivers/hwmon/lm75.c
+++ b/drivers/hwmon/lm75.c
@@ -352,7 +352,7 @@ static inline int lm75_write_config(stru
 				    u16 clr_mask)
 {
 	return regmap_update_bits(data->regmap, LM75_REG_CONF,
-				  clr_mask | LM75_SHUTDOWN, set_mask);
+				  clr_mask | set_mask | LM75_SHUTDOWN, set_mask);
 }
 
 static irqreturn_t lm75_alarm_handler(int irq, void *private)
