On Wed, Mar 15, 2017 at 05:00:08PM +0200, Roger Quadros wrote:
> Andrew,
>
> On 15/03/17 16:08, Andrew Lunn wrote:
> > On Wed, Mar 15, 2017 at 03:51:27PM +0200, Roger Quadros wrote:
> >> Since commit 3c293f4e08b5 ("net: phy: Trigger state machine on state
> >> change and not polling.")
> >> phy_suspend() doesn't get called as part of phy_stop() for PHYs using
> >> interrupts because the phy state machine is never triggered after a
> >> phy_stop().
> >>
> >> Explicitly trigger the PHY state machine so that it can
> >> see the new PHY state (HALTED) and suspend the PHY.
> >>
> >> Signed-off-by: Roger Quadros <rog...@ti.com>
> >
> > Hi Roger
> >
> > This seems sensible. It mirrors what phy_start() does.
> >
> > Reviewed-by: Andrew Lunn <and...@lunn.ch>
>
> The reason for this being an RFC was the following comment just before
> where I add the phy_trigger_machine()
>
> /* Cannot call flush_scheduled_work() here as desired because
> * of rtnl_lock(), but PHY_HALTED shall guarantee phy_change()
> * will not reenable interrupts.
> */
>
> Is this comment still applicable? If yes, is it OK to call
> phy_trigger_machine() there?
Humm, good question.
My _guess_ would be, calling it with sync=True could
deadlock. sync=False is probably safe. But lets see what Florian says.
>
> >
> > It does however lead to a follow up question. Are there other places
> > phydev->state is changed and it is missing a phy_trigger_machine()?
> >
>
> One other place I think we should add phy_trigger_machine() is
> phy_start_aneg().
Humm, that might get us into a tight loop.
phy_start_aneg() kicks the phy driver to start autoneg and sets
phydev->state = PHY_AN.
phy_trigger_machine() triggers the state machine immediately.
In state PHY_AN, we check if aneg is done. If not, it sets needs_aneg
= true. At the end of the state machine, this then calls
phy_start_aneg(), and it all starts again.
We are missing the 1s delay we have with polling. So for
phy_start_aneg(), we might need a phy_delayed_trigger_machine(), which
waits a second before doing anything?
Andrew
