On 18.03.2021 10:09, 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.
Fixed this by adding a check of PHY ID equals to all zeroes.
Fixes: ee951005e95e ("net: phy: clean up get_phy_c22_id() invalid ID handling") Cc: stable@vger.kernel.org Reviewed-by: Voon Weifeng voon.weifeng@intel.com Signed-off-by: Wong Vee Khee vee.khee.wong@intel.com
v2 changelog:
- added fixes tag
- marked for net instead of net-next
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 cc38e326405a..c12c30254c11 100644 --- a/drivers/net/phy/phy_device.c +++ b/drivers/net/phy/phy_device.c @@ -809,8 +809,8 @@ 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;
+ the authors of 0cc8fecf041d ("net: phy: Allow mdio buses to auto-probe c45 devices")
In case of MDIOBUS_C22_C45 we probe c22 first, and then c45. This causes problems with c45 PHY's that have rudimentary c22 support and return 0 when reading the c22 PHY ID registers.
Is there a specific reason why c22 is probed first? Reversing the order would solve the issue we speak about here. c45-probing of c22-only PHY's shouldn't return false positives (at least at a first glance).