Re: [PATCH net-next 1/1] net: phy: fix invalid phy id when probe using C22
From: Heiner Kallweit <hkallweit1@gmail.com>
Date: 2021-03-17 08:16:11
Also in:
lkml, stable
On 16.03.2021 09:57, Wong Vee Khee wrote:
When using Clause-22 to probe for PHY devices such as the Marvell 88E2110, PHY ID with value 0 is read from the MII PHYID registers which caused the PHY framework failed to attach the Marvell PHY driver.
The issue occurs with a MAC driver that sets MDIO bus capability flag MDIOBUS_C22_C45, like stmmac? Or what is the affected MAC driver? And if you state it's a fix, a Fixes tag would be needed.
quoted hunk ↗ jump to hunk
Fixed this by adding a check of PHY ID equals to all zeroes. Cc: stable@vger.kernel.org Reviewed-by: Voon Weifeng <redacted> Signed-off-by: Wong Vee Khee <redacted> --- drivers/net/phy/phy_device.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)diff --git a/drivers/net/phy/phy_device.c b/drivers/net/phy/phy_device.c index a009d1769b08..f1afc00fcba2 100644 --- a/drivers/net/phy/phy_device.c +++ b/drivers/net/phy/phy_device.c@@ -820,8 +820,8 @@ static int get_phy_c22_id(struct mii_bus *bus, int addr, u32 *phy_id) *phy_id |= phy_reg; - /* If the phy_id is mostly Fs, there is no device there */ - if ((*phy_id & 0x1fffffff) == 0x1fffffff) + /* If the phy_id is mostly Fs or all zeroes, there is no device there */ + if (((*phy_id & 0x1fffffff) == 0x1fffffff) || (*phy_id == 0)) return -ENODEV; return 0;