From: Igor Pylypiv <igor.pylypiv@gmail.com>
Date: Wed, 28 Feb 2018 08:59:12 +0000 (-0800)
Subject: watchdog: f71808e_wdt: Fix magic close handling
X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=7bd3e7b743956afbec30fb525bc3c5e22e3d475c;p=linux.git

watchdog: f71808e_wdt: Fix magic close handling

Watchdog close is "expected" when any byte is 'V' not just the last one.
Writing "V" to the device fails because the last byte is the end of string.

$ echo V > /dev/watchdog
f71808e_wdt: Unexpected close, not stopping watchdog!

Signed-off-by: Igor Pylypiv <igor.pylypiv@gmail.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
---

diff --git a/drivers/watchdog/f71808e_wdt.c b/drivers/watchdog/f71808e_wdt.c
index e0678c14480f2..3a33c5344bd5e 100644
--- a/drivers/watchdog/f71808e_wdt.c
+++ b/drivers/watchdog/f71808e_wdt.c
@@ -566,7 +566,8 @@ static ssize_t watchdog_write(struct file *file, const char __user *buf,
 				char c;
 				if (get_user(c, buf + i))
 					return -EFAULT;
-				expect_close = (c == 'V');
+				if (c == 'V')
+					expect_close = true;
 			}
 
 			/* Properly order writes across fork()ed processes */