From: Lukas Wunner <lukas@wunner•de>
To: Andrew Lunn <andrew@lunn•ch>
Cc: Marek Szyprowski <m.szyprowski@samsung•com>,
"David S. Miller" <davem@davemloft•net>,
Jakub Kicinski <kuba@kernel•org>, Paolo Abeni <pabeni@redhat•com>,
Eric Dumazet <edumazet@google•com>,
netdev@vger•kernel.org, linux-usb@vger•kernel.org,
Steve Glendinning <steve.glendinning@shawell•net>,
UNGLinuxDriver@microchip•com, Oliver Neukum <oneukum@suse•com>,
Andre Edich <andre.edich@microchip•com>,
Oleksij Rempel <linux@rempel-privat•de>,
Martyn Welch <martyn.welch@collabora•com>,
Gabriel Hojda <ghojda@yo2urs•ro>,
Christoph Fritz <chf.fritz@googlemail•com>,
Lino Sanfilippo <LinoSanfilippo@gmx•de>,
Philipp Rosenberger <p.rosenberger@kunbus•com>,
Heiner Kallweit <hkallweit1@gmail•com>,
Russell King <linux@armlinux•org.uk>,
Ferry Toth <fntoth@gmail•com>,
Krzysztof Kozlowski <krzk@kernel•org>,
'Linux Samsung SOC' <linux-samsung-soc@vger•kernel.org>
Subject: Re: [PATCH net-next v3 5/7] usbnet: smsc95xx: Forward PHY interrupts to PHY driver to avoid polling
Date: Tue, 24 May 2022 14:13:41 +0200 [thread overview]
Message-ID: <20220524121341.GA10702@wunner.de> (raw)
In-Reply-To: <Yowv95s7g7Ou5U8J@lunn.ch>
On Tue, May 24, 2022 at 03:08:07AM +0200, Andrew Lunn wrote:
> > @@ -976,6 +977,25 @@ static irqreturn_t phy_interrupt(int irq, void *phy_dat)
> > struct phy_driver *drv = phydev->drv;
> > irqreturn_t ret;
> >
> > + if (IS_ENABLED(CONFIG_PM_SLEEP) &&
> > + (phydev->mdio.dev.power.is_prepared ||
> > + phydev->mdio.dev.power.is_suspended)) {
> > + struct net_device *netdev = phydev->attached_dev;
> > +
> > + if (netdev) {
> > + struct device *parent = netdev->dev.parent;
> > +
> > + if (netdev->wol_enabled)
> > + pm_system_wakeup();
> > + else if (device_may_wakeup(&netdev->dev))
> > + pm_wakeup_dev_event(&netdev->dev, 0, true);
> > + else if (parent && device_may_wakeup(parent))
> > + pm_wakeup_dev_event(parent, 0, true);
> > + }
> > +
> > + return IRQ_HANDLED;
>
> I'm not sure you can just throw the interrupt away. There have been
> issues with WoL, where the WoL signal has been applied to a PMC, not
> an actual interrupt. Yet the PHY driver assumes it is an
> interrupt. And in order for WoL to work correctly, it needs the
> interrupt handler to be called. We said the hardware is broken, WoL
> cannot work for that setup.
>
> Here you have correct hardware, but you are throwing the interrupt
> away, which will have the same result. So i think you need to abort
> the suspend, get the bus working again, and call the interrupt
> handler. If this is a WoL interrupt you are supposed to be waking up
> anyway.
mdio_bus_phy_resume() does trigger the state machine via
phy_start_machine(), so link state changes *are* detected after wakeup.
But you're saying that's not sufficient and you really want the
PHY driver's IRQ handler to be called, do I understand that correctly?
That could be achieved with a flag indicating that the IRQ handler
needs to be rerun after resume. A simple invocation of irq_wake_thread()
will then achieve that.
It has also occurred to me that not clearing the IRQ may lead to
an interrupt storm if it's level-triggered. So I need to disable
the IRQ and re-enable it after the PHY has been resumed.
Back to the drawing board...
Thanks,
Lukas
next prev parent reply other threads:[~2022-05-24 12:13 UTC|newest]
Thread overview: 40+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-05-12 8:42 [PATCH net-next v3 0/7] Polling be gone on LAN95xx Lukas Wunner
2022-05-12 8:42 ` [PATCH net-next v3 1/7] usbnet: Run unregister_netdev() before unbind() again Lukas Wunner
2022-05-12 8:42 ` [PATCH net-next v3 2/7] usbnet: smsc95xx: Don't clear read-only PHY interrupt Lukas Wunner
2022-05-12 11:57 ` Lukas Wunner
2022-05-12 8:42 ` [PATCH net-next v3 3/7] usbnet: smsc95xx: Don't reset PHY behind PHY driver's back Lukas Wunner
2022-05-12 12:12 ` Lukas Wunner
2022-05-12 8:42 ` [PATCH net-next v3 4/7] usbnet: smsc95xx: Avoid link settings race on interrupt reception Lukas Wunner
2022-05-12 12:15 ` Lukas Wunner
2022-05-12 8:42 ` [PATCH net-next v3 5/7] usbnet: smsc95xx: Forward PHY interrupts to PHY driver to avoid polling Lukas Wunner
2022-05-17 10:18 ` Marek Szyprowski
2022-05-19 19:08 ` Lukas Wunner
2022-05-19 21:22 ` Marek Szyprowski
2022-05-23 9:43 ` Lukas Wunner
2022-05-23 11:38 ` Marek Szyprowski
2022-05-23 12:34 ` Andrew Lunn
2022-05-23 13:47 ` Lukas Wunner
2022-05-24 0:52 ` Andrew Lunn
2022-05-24 1:08 ` Andrew Lunn
2022-05-24 6:16 ` Marek Szyprowski
2022-05-24 12:03 ` Andrew Lunn
2022-05-26 13:55 ` Lukas Wunner
2022-05-24 12:13 ` Lukas Wunner [this message]
2022-06-06 1:28 ` Andrew Lunn
2022-08-26 6:51 ` Marek Szyprowski
2022-08-26 7:19 ` Lukas Wunner
2022-08-26 7:41 ` Marek Szyprowski
2022-08-26 7:53 ` Lukas Wunner
2022-08-26 8:29 ` Marek Szyprowski
2022-08-29 11:40 ` Marek Szyprowski
2022-09-18 19:13 ` Lukas Wunner
2022-09-18 20:41 ` Florian Fainelli
2022-09-18 20:55 ` Lukas Wunner
2022-09-18 22:11 ` Florian Fainelli
2022-09-23 4:20 ` Lukas Wunner
2022-09-22 13:21 ` Marek Szyprowski
2022-05-12 8:42 ` [PATCH net-next v3 6/7] net: phy: smsc: Cache interrupt mask Lukas Wunner
2022-05-12 12:17 ` Lukas Wunner
2022-05-12 8:42 ` [PATCH net-next v3 7/7] net: phy: smsc: Cope with hot-removal in interrupt handler Lukas Wunner
2022-05-12 12:19 ` Lukas Wunner
2022-05-13 10:40 ` [PATCH net-next v3 0/7] Polling be gone on LAN95xx patchwork-bot+netdevbpf
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