[PATCH net-next 1/4] net: dsa: lan9303: Fix lan9303_detect_phy_setup() for MDIO

Egil Hjelmeland
2017-07-28T15:12:43Z

Handle that MDIO read with no response return 0xffff.

Signed-off-by: Egil Hjelmeland <privat@egil-hjelmeland.no>
---
drivers/net/dsa/lan9303-core.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/net/dsa/lan9303-core.c b/drivers/net/dsa/lan9303-core.c
index cd76e61f1fca..9d0ab77edb4a 100644
--- a/drivers/net/dsa/lan9303-core.c
+++ b/drivers/net/dsa/lan9303-core.c
@@ -427,6 +427,7 @@ static int lan9303_detect_phy_setup(struct lan9303 *chip)
* Special reg 18 of phy 3 reads as 0x0000, if 'phy_addr_sel_strap' is 0
* and the IDs are 0-1-2, else it contains something different from
* 0x0000, which means 'phy_addr_sel_strap' is 1 and the IDs are 1-2-3.
+ * 0xffff is returned on MDIO read with no response.
*/
reg = lan9303_port_phy_reg_read(chip, 3, MII_LAN911X_SPECIAL_MODES);
if (reg < 0) {
@@ -434,7 +435,7 @@ static int lan9303_detect_phy_setup(struct lan9303 *chip)
return reg;
}

- if (reg != 0)
+ if ((reg != 0) && (reg != 0xffff))
chip->phy_addr_sel_strap = 1;
else
chip->phy_addr_sel_strap = 0;
--
2.11.0