[PATCH net-next v3 1/2] net: phy: mscc: fix signedness bug in vsc85xx_downshift_get

From: Gustavo A. R. Silva
Date: Tue Oct 16 2018 - 13:35:30 EST

Currently, the error handling for the call to function
phy_read_paged() doesn't work because *reg_val* is of
type u16 (16 bits, unsigned), which makes it impossible
for it to hold a value less than 0.

Fix this by changing the type of variable *reg_val* to int.

Addresses-Coverity-ID: 1473970 ("Unsigned compared against 0")
Fixes: 6a0bfbbe20b0 ("net: phy: mscc: migrate to phy_select/restore_page functions")
Reviewed-by: Quentin Schulz <quentin.schulz@xxxxxxxxxxx>
Signed-off-by: Gustavo A. R. Silva <gustavo@xxxxxxxxxxxxxx>
Changes in v3:
- Post patch to netdev.

Changes in v2:
- Add Quentin's Reviewed-by to the commit log.

drivers/net/phy/mscc.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/phy/mscc.c b/drivers/net/phy/mscc.c
index bffe077..bff56c3 100644
--- a/drivers/net/phy/mscc.c
+++ b/drivers/net/phy/mscc.c
@@ -522,7 +522,7 @@ static int vsc85xx_mdix_set(struct phy_device *phydev, u8 mdix)

static int vsc85xx_downshift_get(struct phy_device *phydev, u8 *count)
- u16 reg_val;
+ int reg_val;

reg_val = phy_read_paged(phydev, MSCC_PHY_PAGE_EXTENDED,