From 7d82fcc9d9e81241778aaa22fda7be753e237d86 Mon Sep 17 00:00:00 2001
From: Guenter Roeck <linux@roeck-us.net>
Date: Thu, 8 Aug 2019 12:00:18 -0700
Subject: [PATCH] hwmon: (lm75) Fix write operations for negative temperatures
Git-commit: 7d82fcc9d9e81241778aaa22fda7be753e237d86
Patch-mainline: v5.4-rc1
References: bsc#1051510
Writes into limit registers fail if the temperature written is negative.
The regmap write operation checks the value range, regmap_write accepts
an unsigned int as parameter, and the temperature value passed to
regmap_write is kept in a variable declared as long. Negative values
are converted large unsigned integers, which fails the range check.
Fix by type casting the temperature to u16 when calling regmap_write().
Cc: Iker Perez del Palomar Sustatxa <iker.perez@codethink.co.uk>
Fixes: e65365fed87f ("hwmon: (lm75) Convert to use regmap")
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Acked-by: Takashi Iwai <tiwai@suse.de>
---
drivers/hwmon/lm75.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/hwmon/lm75.c b/drivers/hwmon/lm75.c
index ce5ec403ec73..cbabab7ac788 100644
--- a/drivers/hwmon/lm75.c
+++ b/drivers/hwmon/lm75.c
@@ -154,7 +154,7 @@ static int lm75_write(struct device *dev, enum hwmon_sensor_types type,
temp = DIV_ROUND_CLOSEST(temp << (resolution - 8),
1000) << (16 - resolution);
- return regmap_write(data->regmap, reg, temp);
+ return regmap_write(data->regmap, reg, (u16)temp);
}
static umode_t lm75_is_visible(const void *data, enum hwmon_sensor_types type,
--
2.16.4