On Wed, Oct 12, 2016 at 10:14:53PM +0200, Andrew Lunn wrote:
> The phy_start() is used to indicate the PHY is now ready to do its
> work. The state is changed, normally to PHY_UP which means that both
> the MAC and the PHY are ready.
>
> If the phy driver is using polling, when the next poll happens, the
> state machine notices the PHY is now in PHY_UP, and kicks off
> auto-negotiation, if needed.
>
> If however, the PHY is using interrupts, there is no polling. The phy
> is stuck in PHY_UP until the next interrupt comes along. And there is
> no reason for the PHY to interrupt.
>
> Have phy_start() schedule the state machine to run, which both speeds
> up the polling use case, and makes the interrupt use case actually
> work.
>
> This problems exists whenever there is a state change which will not
> cause an interrupt. Trigger the state machine in these cases,
> e.g. phy_error().
>
> Signed-off-by: Andrew Lunn <and...@lunn.ch>
> Cc: Kyle Roeschley <kyle.roesch...@ni.com>
> ---
>
> This should be applied to stable, but i've no idea what fixes: tag to
> use. It could be phylib has been broken since interrupts were added?
>
This patched fixed another problem had with the phy state machine which was
caused by d5c3d8465 ("net: phy: Avoid polling PHY with PHY_IGNORE_INTERRUPTS").
That might be the commit you're looking for. Also,
Tested-by: Kyle Roeschley <kyle.roesch...@ni.com>
> drivers/net/phy/phy.c | 22 ++++++++++++++++++++--
> 1 file changed, 20 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/net/phy/phy.c b/drivers/net/phy/phy.c
> index c6f66832a1a6..f424b867f73e 100644
> --- a/drivers/net/phy/phy.c
> +++ b/drivers/net/phy/phy.c
> @@ -608,6 +608,21 @@ void phy_start_machine(struct phy_device *phydev)
> }
>
> /**
> + * phy_trigger_machine - trigger the state machine to run
> + *
> + * @phydev: the phy_device struct
> + *
> + * Description: There has been a change in state which requires that the
> + * state machine runs.
> + */
> +
You've got a bonus newline here.
> +static void phy_trigger_machine(struct phy_device *phydev)
> +{
> + cancel_delayed_work_sync(&phydev->state_queue);
> + queue_delayed_work(system_power_efficient_wq, &phydev->state_queue, 0);
> +}
> +
> +/**
> * phy_stop_machine - stop the PHY state machine tracking
> * @phydev: target phy_device struct
> *
> @@ -639,6 +654,8 @@ static void phy_error(struct phy_device *phydev)
> mutex_lock(&phydev->lock);
> phydev->state = PHY_HALTED;
> mutex_unlock(&phydev->lock);
> +
> + phy_trigger_machine(phydev);
> }
>
> /**
> @@ -800,8 +817,7 @@ void phy_change(struct work_struct *work)
> }
>
> /* reschedule state queue work to run as soon as possible */
> - cancel_delayed_work_sync(&phydev->state_queue);
> - queue_delayed_work(system_power_efficient_wq, &phydev->state_queue, 0);
> + phy_trigger_machine(phydev);
> return;
>
> ignore:
> @@ -890,6 +906,8 @@ void phy_start(struct phy_device *phydev)
> /* if phy was suspended, bring the physical link up again */
> if (do_resume)
> phy_resume(phydev);
> +
> + phy_trigger_machine(phydev);
> }
> EXPORT_SYMBOL(phy_start);
>
> --
> 2.9.3
>
--
Kyle Roeschley
Software Engineer
National Instruments
