From f50b6805dbb993152025ec04dea094c40cc93a0c Mon Sep 17 00:00:00 2001
From: Colin Ian King <colin.king@canonical.com>
Date: Sun, 13 Oct 2019 23:00:16 +0100
Subject: [PATCH] 8250-men-mcb: fix error checking when get_num_ports returns -ENODEV
Git-commit: f50b6805dbb993152025ec04dea094c40cc93a0c
Patch-mainline: v5.4-rc5
References: git-fixes bnc#1151927 5.3.10

The current checking for failure on the number of ports fails when
-ENODEV is returned from the call to get_num_ports. Fix this by making
num_ports and loop counter i signed rather than unsigned ints. Also
add check for num_ports being less than zero to check for -ve error
returns.

Addresses-coverity: ("Unsigned compared against 0")
Fixes: e2fea54e4592 ("8250-men-mcb: add support for 16z025 and 16z057")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Reviewed-by: Michael Moese <mmoese@suse.de>
Link: https://lore.kernel.org/r/20191013220016.9369-1-colin.king@canonical.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Takashi Iwai <tiwai@suse.de>

---
 drivers/tty/serial/8250/8250_men_mcb.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/tty/serial/8250/8250_men_mcb.c b/drivers/tty/serial/8250/8250_men_mcb.c
index 02c5aff58a74..8df89e9cd254 100644
--- a/drivers/tty/serial/8250/8250_men_mcb.c
+++ b/drivers/tty/serial/8250/8250_men_mcb.c
@@ -72,8 +72,8 @@ static int serial_8250_men_mcb_probe(struct mcb_device *mdev,
 {
 	struct serial_8250_men_mcb_data *data;
 	struct resource *mem;
-	unsigned int num_ports;
-	unsigned int i;
+	int num_ports;
+	int i;
 	void __iomem *membase;
 
 	mem = mcb_get_resource(mdev, IORESOURCE_MEM);
@@ -88,7 +88,7 @@ static int serial_8250_men_mcb_probe(struct mcb_device *mdev,
 	dev_dbg(&mdev->dev, "found a 16z%03u with %u ports\n",
 		mdev->id, num_ports);
 
-	if (num_ports == 0 || num_ports > 4) {
+	if (num_ports <= 0 || num_ports > 4) {
 		dev_err(&mdev->dev, "unexpected number of ports: %u\n",
 			num_ports);
 		return -ENODEV;
@@ -133,7 +133,7 @@ static int serial_8250_men_mcb_probe(struct mcb_device *mdev,
 
 static void serial_8250_men_mcb_remove(struct mcb_device *mdev)
 {
-	unsigned int num_ports, i;
+	int num_ports, i;
 	struct serial_8250_men_mcb_data *data = mcb_get_drvdata(mdev);
 
 	if (!data)
-- 
2.16.4