From mboxrd@z Thu Jan 1 00:00:00 1970 From: Kyle Roeschley Subject: Re: [PATCH net-next] net: phy: Trigger state machine on state change and not polling. Date: Wed, 12 Oct 2016 16:44:31 -0500 Message-ID: <20161012214430.akx655amb4ow6kz5@senary> References: <1476303294-14944-1-git-send-email-andrew@lunn.ch> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Cc: David Miller , netdev , Florian Fainelli To: Andrew Lunn Return-path: Received: from mail-sn1nam01on0099.outbound.protection.outlook.com ([104.47.32.99]:53280 "EHLO NAM01-SN1-obe.outbound.protection.outlook.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1750898AbcJLV74 (ORCPT ); Wed, 12 Oct 2016 17:59:56 -0400 Content-Disposition: inline In-Reply-To: <1476303294-14944-1-git-send-email-andrew@lunn.ch> Sender: netdev-owner@vger.kernel.org List-ID: 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 > Cc: Kyle Roeschley > --- > > 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 > 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