Re: [PATCH net] net: phy: Warn about incorrect mdio_bus_phy_resume() state

Jakub Kicinski
2022-09-22T12:31:20Z

On Mon, 1 Aug 2022 16:34:03 -0700 Florian Fainelli wrote:
> Calling mdio_bus_phy_resume() with neither the PHY state machine set to
> PHY_HALTED nor phydev->mac_managed_pm set to true is a good indication
> that we can produce a race condition looking like this:
>
> CPU0 CPU1
> bcmgenet_resume
> -> phy_resume
> -> phy_init_hw
> -> phy_start
> -> phy_resume
> phy_start_aneg()
> mdio_bus_phy_resume
> -> phy_resume
> -> phy_write(..., BMCR_RESET)
> -> usleep() -> phy_read()
>
> with the phy_resume() function triggering a PHY behavior that might have
> to be worked around with (see bf8bfc4336f7 ("net: phy: broadcom: Fix
> brcm_fet_config_init()") for instance) that ultimately leads to an error
> reading from the PHY.

Hi Florian! There were some follow ups on this one, were all the known
reports covered at this point or there are still platforms to tweak?