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    SubjectRe: [PATCH 6/6] net: phy: Stop 'phy-state-machine' and 'phy_change' work on remove
    (don't top post please)

    On 27/10/15 08:53, Frode Isaksen wrote:
    > What will you need in the oops ? I presume you don' want everything or ?
    >
    > The PHY state machine is not stopped with a PHY disconnect.

    It is stopped with a phy_disconnect():

    /**
    * phy_disconnect - disable interrupts, stop state machine, and detach a PHY
    * device
    * @phydev: target phy_device struct
    */
    void phy_disconnect(struct phy_device *phydev)
    {
    if (phydev->irq > 0)
    phy_stop_interrupts(phydev);

    phy_stop_machine(phydev);

    phydev->adjust_link = NULL;

    phy_detach(phydev);
    }


    > However, the
    > 'phy-change' work is cancelled, so cancelling this work in the remove
    > function maybe not needed. I will verify ASAP.
    >
    > Frode
    >
    > 2015-10-27 16:40 GMT+01:00 Florian Fainelli <f.fainelli@gmail.com
    > <mailto:f.fainelli@gmail.com>>:
    >
    > On 27/10/15 07:49, Neil Armstrong wrote:
    > > Avoids:
    > > Unable to handle kernel NULL pointer dereference at virtual address 00000064
    > > Workqueue: events_power_efficient phy_state_machine
    > > PC is at phy_state_machine+0x28/0x480
    >
    > Stripped down oops can sometimes be missing critical pieces of
    > information to help debug the problem, is there a reason why this is
    > being obfuscated?
    >
    > You are supposed to stop the PHY state machine by calling
    > phy_disconnect() is it possible that this is missing?
    >
    > >
    > > Signed-off-by: Frode Isaksen <fisaksen@baylibre.com
    > <mailto:fisaksen@baylibre.com>>
    > > Signed-off-by: Neil Armstrong <narmstrong@baylibre.com
    > <mailto:narmstrong@baylibre.com>>
    > > ---
    > > drivers/net/phy/phy_device.c | 6 ++++++
    > > 1 file changed, 6 insertions(+)
    > >
    > > diff --git a/drivers/net/phy/phy_device.c
    > b/drivers/net/phy/phy_device.c
    > > index 3833891..b5b6c1b 100644
    > > --- a/drivers/net/phy/phy_device.c
    > > +++ b/drivers/net/phy/phy_device.c
    > > @@ -1348,6 +1348,12 @@ static int phy_remove(struct device *dev)
    > > phydev->state = PHY_DOWN;
    > > mutex_unlock(&phydev->lock);
    > >
    > > + cancel_delayed_work_sync(&phydev->state_queue);
    > > + flush_delayed_work(&phydev->state_queue);
    > > +
    > > + cancel_work_sync(&phydev->phy_queue);
    > > + flush_work(&phydev->phy_queue);
    > > +
    > > if (phydev->drv->remove)
    > > phydev->drv->remove(phydev);
    > > phydev->drv = NULL;
    > >
    >
    >
    > --
    > Florian
    >
    >


    --
    Florian


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