[PATCH AUTOSEL 4.19 22/38] 8250-men-mcb: fix error checking when get_num_ports returns -ENODEV

Sasha Levin
2019-10-30T16:00:46Z

From: Colin Ian King <colin.king@canonical.com>

[ Upstream commit f50b6805dbb993152025ec04dea094c40cc93a0c ]

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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
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 127017cc41d92..057b1eaf6d2eb 100644
--- a/drivers/tty/serial/8250/8250_men_mcb.c
+++ b/drivers/tty/serial/8250/8250_men_mcb.c
@@ -71,8 +71,8 @@ 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);
@@ -87,7 +87,7 @@ 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;
@@ -132,7 +132,7 @@ 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)
--
2.20.1