serial: sc16is7xx: remove wasteful static buffer in sc16is7xx_regmap_name()

Using a static buffer inside sc16is7xx_regmap_name() was a convenient and
simple way to set the regmap name without having to allocate and free a
buffer each time it is called. The drawback is that the static buffer
wastes memory for nothing once regmap is fully initialized.

Remove static buffer and use constant strings instead.

This also avoids a truncation warning when using "%d" or "%u" in snprintf
which was flagged by kernel test robot.

Fixes: 3837a0379533 ("serial: sc16is7xx: improve regmap debugfs by using one regmap per port")
Cc:  <stable@vger.kernel.org> # 6.1.x: 3837a03 serial: sc16is7xx: improve regmap debugfs by using one regmap per port
Suggested-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Hugo Villeneuve <hvilleneuve@dimonoff.com>
Link: https://lore.kernel.org/r/20231211171353.2901416-2-hugo@hugovil.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/tty/serial/sc16is7xx.c b/drivers/tty/serial/sc16is7xx.c
index 9cb503169a48a43ad1962d3b807fa50aef33100f..8d1de4982b65a66b355db6202fb8ee3fb429f1b1 100644 (file)
--- a/drivers/tty/serial/sc16is7xx.c
+++ b/drivers/tty/serial/sc16is7xx.c
@@ -1708,13 +1708,15 @@ static struct regmap_config regcfg = {
        .max_register = SC16IS7XX_EFCR_REG,
 };
 
-static const char *sc16is7xx_regmap_name(unsigned int port_id)
+static const char *sc16is7xx_regmap_name(u8 port_id)
 {
-       static char buf[6];
-
-       snprintf(buf, sizeof(buf), "port%d", port_id);
-
-       return buf;
+       switch (port_id) {
+       case 0: return "port0";
+       case 1: return "port1";
+       default:
+               WARN_ON(true);
+               return NULL;
+       }
 }
 
 static unsigned int sc16is7xx_regmap_port_mask(unsigned int port_id)