Re: [PATCH net-next v3 5/7] usbnet: smsc95xx: Forward PHY interrupts to PHY driver to avoid polling

From: Andrew Lunn <andrew@lunn.ch>
To: Lukas Wunner <lukas@wunner.de>
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: Mon, 23 May 2022 14:34:49 +0200	[thread overview]
Message-ID: <Yot/ad/Ch7iGYnGB@lunn.ch> (raw)
In-Reply-To: <20220523094343.GA7237@wunner.de>

> --- a/drivers/net/phy/phy_device.c
> +++ b/drivers/net/phy/phy_device.c
> @@ -283,8 +283,11 @@ static __maybe_unused int mdio_bus_phy_suspend(struct device *dev)
>  	 * may call phy routines that try to grab the same lock, and that may
>  	 * lead to a deadlock.
>  	 */
> -	if (phydev->attached_dev && phydev->adjust_link)
> +	if (phydev->attached_dev && phydev->adjust_link) {
> +		if (phy_interrupt_is_valid(phydev))
> +			synchronize_irq(phydev->irq);
>  		phy_stop_machine(phydev);
> +	}

What is this hunk trying to achieve? As far as i know, interrupts have
not been disabled. So as soon as the call to synchronize_irq()
finishes, could well be another interrupt happens.

	  Andrew