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Commit 8e346e15 authored by Florian Fainelli's avatar Florian Fainelli Committed by David S. Miller
Browse files

net: phy: bcm7xxx: workaround MDIO management controller initial read 



The initial MDIO read or write towards the BCM7xxx integrated PHY may
fail, workaround this by inserting a dummy MII_BMSR read to force the
MDIO management controller to see at least one valid transaction and get
out of stuck state out of reset.

Signed-off-by: default avatarFlorian Fainelli <f.fainelli@gmail.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 8031612d

drivers/net/phy/bcm7xxx.c

+7 −0
Original line number Diff line number Diff line
@@ -246,6 +246,13 @@ static int bcm7xxx_28nm_config_init(struct phy_device *phydev) 
	pr_info_once("%s: %s PHY revision: 0x%02x, patch: %d\n",

		     dev_name(&phydev->dev), phydev->drv->name, rev, patch);



	/* Dummy read to a register to workaround an issue upon reset where the

	 * internal inverter may not allow the first MDIO transaction to pass

	 * the MDIO management controller and make us return 0xffff for such

	 * reads.

	 */

	phy_read(phydev, MII_BMSR);



	switch (rev) {

	case 0xb0:

		ret = bcm7xxx_28nm_b0_afe_config_init(phydev);