[PATCH 4.9 207/271] net: ethernet: stmmac: Fix signedness bug in ipq806x_gmac_of_parse()

From: Greg Kroah-Hartman
Date: Tue Jan 28 2020 - 09:23:23 EST


From: Dan Carpenter <dan.carpenter@xxxxxxxxxx>

[ Upstream commit 231042181dc9d6122c6faba64e99ccb25f13cc6c ]

The "gmac->phy_mode" variable is an enum and in this context GCC will
treat it as an unsigned int so the error handling will never be
triggered.

Fixes: b1c17215d718 ("stmmac: add ipq806x glue layer")
Signed-off-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
drivers/net/ethernet/stmicro/stmmac/dwmac-ipq806x.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac-ipq806x.c b/drivers/net/ethernet/stmicro/stmmac/dwmac-ipq806x.c
index 866444b6c82fa..11a4a81b0397c 100644
--- a/drivers/net/ethernet/stmicro/stmmac/dwmac-ipq806x.c
+++ b/drivers/net/ethernet/stmicro/stmmac/dwmac-ipq806x.c
@@ -203,7 +203,7 @@ static int ipq806x_gmac_of_parse(struct ipq806x_gmac *gmac)
struct device *dev = &gmac->pdev->dev;

gmac->phy_mode = of_get_phy_mode(dev->of_node);
- if (gmac->phy_mode < 0) {
+ if ((int)gmac->phy_mode < 0) {
dev_err(dev, "missing phy mode property\n");
return -EINVAL;
}
--
2.20.1