[PATCH] 8250_men_mcb: Fix unsigned comparison with less than zero

[PATCH] 8250_men_mcb: Fix unsigned comparison with less than zero

[Jiapeng Chong]

The data->line[i] is defined as unsigned int type, if(data->line[i] < 0)
is invalid, so replace data->line[i] with res.

./drivers/tty/serial/8250/8250_men_mcb.c:223:6-19: WARNING: Unsigned expression compared with zero: data->line[i] < 0.

Reported-by: Abaci Robot <abaci@linux.alibaba.com>
Closes: https://bugzilla.openanolis.cn/show_bug.cgi?id=6088
Signed-off-by: Jiapeng Chong <jiapeng.chong@linux.alibaba.com>
---
 drivers/tty/serial/8250/8250_men_mcb.c | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/drivers/tty/serial/8250/8250_men_mcb.c b/drivers/tty/serial/8250/8250_men_mcb.c
index 5f301195575d..c27c52d18dfa 100644
--- a/drivers/tty/serial/8250/8250_men_mcb.c
+++ b/drivers/tty/serial/8250/8250_men_mcb.c
@@ -222,11 +222,13 @@ static int serial_8250_men_mcb_probe(struct mcb_device *mdev,
 					    + data->offset[i];
 
 		/* ok, register the port */
-		data->line[i] = serial8250_register_8250_port(&uart);
-		if (data->line[i] < 0) {
+		res = serial8250_register_8250_port(&uart);
+		if (res < 0) {
 			dev_err(&mdev->dev, "unable to register UART port\n");
-			return data->line[i];
+			return res;
 		}
+
+		data->line[i] = res;
 		dev_info(&mdev->dev, "found MCB UART: ttyS%d\n", data->line[i]);
 	}
 
-- 
2.20.1.7.g153144c

Re: [PATCH] 8250_men_mcb: Fix unsigned comparison with less than zero

[Andy Shevchenko]

On Thu, Aug 03, 2023 at 04:47:53PM +0800, Jiapeng Chong wrote:
> The data->line[i] is defined as unsigned int type, if(data->line[i] < 0)
> is invalid, so replace data->line[i] with res.
> 
> ./drivers/tty/serial/8250/8250_men_mcb.c:223:6-19: WARNING: Unsigned expression compared with zero: data->line[i] < 0.

Having

 WARNING: Unsigned expression compared with zero: data->line[i] < 0.

is enough.

Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>

-- 
With Best Regards,
Andy Shevchenko