[PATCH][next] net: phy: bcm54140: fix less than zero comparison on an unsigned

[PATCH][next] net: phy: bcm54140: fix less than zero comparison on an unsigned

[Colin King]

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

Currently the unsigned variable tmp is being checked for an negative
error return from the call to bcm_phy_read_rdb and this can never
be true since tmp is unsigned.  Fix this by making tmp a plain int.

Addresses-Coverity: ("Unsigned compared against 0")
Fixes: 4406d36dfdf1 ("net: phy: bcm54140: add hwmon support")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
---
 drivers/net/phy/bcm54140.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/net/phy/bcm54140.c b/drivers/net/phy/bcm54140.c
index aa854477e06a..7341f0126cc4 100644
--- a/drivers/net/phy/bcm54140.c
+++ b/drivers/net/phy/bcm54140.c
@@ -191,7 +191,8 @@ static int bcm54140_hwmon_read_alarm(struct device *dev, unsigned int bit,
 static int bcm54140_hwmon_read_temp(struct device *dev, u32 attr, long *val)
 {
 	struct phy_device *phydev = dev_get_drvdata(dev);
-	u16 reg, tmp;
+	u16 reg;
+	int tmp;
 
 	switch (attr) {
 	case hwmon_temp_input:
@@ -224,7 +225,8 @@ static int bcm54140_hwmon_read_in(struct device *dev, u32 attr,
 				  int channel, long *val)
 {
 	struct phy_device *phydev = dev_get_drvdata(dev);
-	u16 bit, reg, tmp;
+	u16 bit, reg;
+	int tmp;
 
 	switch (attr) {
 	case hwmon_in_input:
-- 
2.25.1

Re: [PATCH][next] net: phy: bcm54140: fix less than zero comparison on an unsigned

[Andrew Lunn]

On Thu, Apr 23, 2020 at 03:10:16PM +0100, Colin King wrote:
> From: Colin Ian King <colin.king@canonical.com>
> 
> Currently the unsigned variable tmp is being checked for an negative
> error return from the call to bcm_phy_read_rdb and this can never
> be true since tmp is unsigned.  Fix this by making tmp a plain int.
> 
> Addresses-Coverity: ("Unsigned compared against 0")

I thought 0 was unsigned?

> Fixes: 4406d36dfdf1 ("net: phy: bcm54140: add hwmon support")
> Signed-off-by: Colin Ian King <colin.king@canonical.com>

Reviewed-by: Andrew Lunn <andrew@lunn.ch>

    Andrew

Re: [PATCH][next] net: phy: bcm54140: fix less than zero comparison on an unsigned

[Colin Ian King]

On 23/04/2020 15:37, Andrew Lunn wrote:
> On Thu, Apr 23, 2020 at 03:10:16PM +0100, Colin King wrote:
>> From: Colin Ian King <colin.king@canonical.com>
>>
>> Currently the unsigned variable tmp is being checked for an negative
>> error return from the call to bcm_phy_read_rdb and this can never
>> be true since tmp is unsigned.  Fix this by making tmp a plain int.
>>
>> Addresses-Coverity: ("Unsigned compared against 0")
> 
> I thought 0 was unsigned?

yeah, misleading message from the static analyzer methinks

> 
>> Fixes: 4406d36dfdf1 ("net: phy: bcm54140: add hwmon support")
>> Signed-off-by: Colin Ian King <colin.king@canonical.com>
> 
> Reviewed-by: Andrew Lunn <andrew@lunn.ch>
> 
>     Andrew
> 

Re: [PATCH][next] net: phy: bcm54140: fix less than zero comparison on an unsigned

[Michael Walle]

Am 2020-04-23 16:10, schrieb Colin King:
> From: Colin Ian King <colin.king@canonical.com>
> 
> Currently the unsigned variable tmp is being checked for an negative
> error return from the call to bcm_phy_read_rdb and this can never
> be true since tmp is unsigned.  Fix this by making tmp a plain int.
> 
> Addresses-Coverity: ("Unsigned compared against 0")
> Fixes: 4406d36dfdf1 ("net: phy: bcm54140: add hwmon support")
> Signed-off-by: Colin Ian King <colin.king@canonical.com>

FWIW since Andrew already reviewed it:

Reviewed-by: Michael Walle <michael@walle.cc>

-michael

Re: [PATCH][next] net: phy: bcm54140: fix less than zero comparison on an unsigned

[David Miller]

From: Colin King <colin.king@canonical.com>
Date: Thu, 23 Apr 2020 15:10:16 +0100

> From: Colin Ian King <colin.king@canonical.com>
> 
> Currently the unsigned variable tmp is being checked for an negative
> error return from the call to bcm_phy_read_rdb and this can never
> be true since tmp is unsigned.  Fix this by making tmp a plain int.
> 
> Addresses-Coverity: ("Unsigned compared against 0")
> Fixes: 4406d36dfdf1 ("net: phy: bcm54140: add hwmon support")
> Signed-off-by: Colin Ian King <colin.king@canonical.com>

Applied.