net: phy: mdio-gpio: Handle phy_ignore_ta_mask

Update mdiobb_read() to read whether the PHY has a broken turn-around,
and if it does, ignore it to make the read succeeed.
Signed-off-by: NFlorian Fainelli <f.fainelli@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

drivers/net/phy/mdio-bitbang.c

@@ -165,8 +165,11 @@ static int mdiobb_read(struct mii_bus *bus, int phy, int reg)
 
 	ctrl->ops->set_mdio_dir(ctrl, 0);
 
-	/* check the turnaround bit: the PHY should be driving it to zero */
-	if (mdiobb_get_bit(ctrl) != 0) {
+	/* check the turnaround bit: the PHY should be driving it to zero, if this
+	 * PHY is listed in phy_ignore_ta_mask as having broken TA, skip that
+	 */
+	if (mdiobb_get_bit(ctrl) != 0 &&
+	    !(bus->phy_ignore_ta_mask & (1 << phy))) {
 		/* PHY didn't drive TA low -- flush any bits it
 		 * may be trying to send.
 		 */