From: Justin Chen <justin.chen@xxxxxxxxxxxx> [ Upstream commit 096516d092d54604d590827d05b1022c8f326639 ] The 54810 does not support c45. The mmd_phy_indirect accesses return arbirtary values leading to odd behavior like saying it supports EEE when it doesn't. We also see that reading/writing these non-existent MMD registers leads to phy instability in some cases. Fixes: b14995ac2527 ("net: phy: broadcom: Add BCM54810 PHY entry") Signed-off-by: Justin Chen <justin.chen@xxxxxxxxxxxx> Reviewed-by: Florian Fainelli <florian.fainelli@xxxxxxxxxxxx> Link: https://lore.kernel.org/r/1691901708-28650-1-git-send-email-justin.chen@xxxxxxxxxxxx Signed-off-by: Jakub Kicinski <kuba@xxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- drivers/net/phy/broadcom.c | 13 +++++++++++++ 1 file changed, 13 insertions(+) diff --git a/drivers/net/phy/broadcom.c b/drivers/net/phy/broadcom.c index 0cde17bd743f3..a664faa8f01f6 100644 --- a/drivers/net/phy/broadcom.c +++ b/drivers/net/phy/broadcom.c @@ -404,6 +404,17 @@ static int bcm54xx_resume(struct phy_device *phydev) return bcm54xx_config_init(phydev); } +static int bcm54810_read_mmd(struct phy_device *phydev, int devnum, u16 regnum) +{ + return -EOPNOTSUPP; +} + +static int bcm54810_write_mmd(struct phy_device *phydev, int devnum, u16 regnum, + u16 val) +{ + return -EOPNOTSUPP; +} + static int bcm54811_config_init(struct phy_device *phydev) { int err, reg; @@ -841,6 +852,8 @@ static struct phy_driver broadcom_drivers[] = { .phy_id_mask = 0xfffffff0, .name = "Broadcom BCM54810", /* PHY_GBIT_FEATURES */ + .read_mmd = bcm54810_read_mmd, + .write_mmd = bcm54810_write_mmd, .config_init = bcm54xx_config_init, .config_aneg = bcm5481_config_aneg, .ack_interrupt = bcm_phy_ack_intr, -- 2.40.1