[PATCH] usb: misc: cytherm: replace deprecated simple_strtoul with kstrtoint

[Jad Keskes]

simple_strtoul() is deprecated in favor of kstrtoint(). The old
function silently accepts garbage input. kstrtoint() returns -EINVAL
so the driver can actually tell the user they typed something stupid
instead of accepting 0 and wondering why the thermometer isn't
responding.

The 0-255 clamping stays the same, just with proper error handling
in front of it now.

Signed-off-by: Jad Keskes <inasj268@xxxxxxxxx>
---
 drivers/usb/misc/cytherm.c | 12 +++++++++---
 1 file changed, 9 insertions(+), 3 deletions(-)

diff --git a/drivers/usb/misc/cytherm.c b/drivers/usb/misc/cytherm.c
index b183df9826bc..81de3fecf3da 100644
--- a/drivers/usb/misc/cytherm.c
+++ b/drivers/usb/misc/cytherm.c
@@ -85,7 +85,9 @@ static ssize_t brightness_store(struct device *dev, struct device_attribute *att
 	if (!buffer)
 		return 0;
 
-	cytherm->brightness = simple_strtoul(buf, NULL, 10);
+	retval = kstrtoint(buf, 10, &cytherm->brightness);
+	if (retval < 0)
+		return retval;
    
 	if (cytherm->brightness > 0xFF)
 		cytherm->brightness = 0xFF;
@@ -217,7 +219,9 @@ static ssize_t port0_store(struct device *dev, struct device_attribute *attr, co
 	if (!buffer)
 		return 0;
 
-	tmp = simple_strtoul(buf, NULL, 10);
+	retval = kstrtoint(buf, 10, &tmp);
+	if (retval < 0)
+		return retval;
    
 	if (tmp > 0xFF)
 		tmp = 0xFF;
@@ -272,7 +276,9 @@ static ssize_t port1_store(struct device *dev, struct device_attribute *attr, co
 	if (!buffer)
 		return 0;
 
-	tmp = simple_strtoul(buf, NULL, 10);
+	retval = kstrtoint(buf, 10, &tmp);
+	if (retval < 0)
+		return retval;
    
 	if (tmp > 0xFF)
 		tmp = 0xFF;
-- 
2.54.0