watchdog: ziirave_wdt: Zero out only what's necessary

Instead of zeroing out all of the packet and then overwriting a
significant portion of those zeros via memcpy(), zero out only a
portion of the packet that is known to not contain any data.

Signed-off-by: Andrey Smirnov <andrew.smirnov@gmail.com>
Cc: Chris Healy <cphealy@gmail.com>
Cc: Guenter Roeck <linux@roeck-us.net>
Cc: Rick Ramstetter <rick@anteaterllc.com>
Cc: linux-watchdog@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Link: https://lore.kernel.org/r/20190812200906.31344-11-andrew.smirnov@gmail.com
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@linux-watchdog.org>

diff --git a/drivers/watchdog/ziirave_wdt.c b/drivers/watchdog/ziirave_wdt.c
index e0f55cb..69694f2 100644 (file)
--- a/drivers/watchdog/ziirave_wdt.c
+++ b/drivers/watchdog/ziirave_wdt.c
@@ -260,8 +260,6 @@ static int __ziirave_firm_write_pkt(struct watchdog_device *wdd,
                return -EMSGSIZE;
        }
 
-       memset(packet, 0, sizeof(packet));
-
        /* Packet length */
        packet[0] = len;
        /* Packet address */
@@ -269,6 +267,7 @@ static int __ziirave_firm_write_pkt(struct watchdog_device *wdd,
        packet[2] = (addr16 & 0xff00) >> 8;
 
        memcpy(packet + 3, data, len);
+       memset(packet + 3 + len, 0, ZIIRAVE_FIRM_PKT_DATA_SIZE - len);
 
        /* Packet checksum */
        for (i = 0; i < len + 3; i++)