RE: [PATCH net] net: phy: skip disabling interrupt when WOL is enabled in shutdown

[Ismail, Mohammad Athari]

> -----Original Message-----
> From: Andrew Lunn <andrew@xxxxxxx>
> Sent: Tuesday, July 6, 2021 9:14 PM
> To: Ling, Pei Lee <pei.lee.ling@xxxxxxxxx>
> Cc: Heiner Kallweit <hkallweit1@xxxxxxxxx>; Russell King
> <linux@xxxxxxxxxxxxxxx>; davem@xxxxxxxxxxxxx; Jakub Kicinski
> <kuba@xxxxxxxxxx>; Ioana Ciornei <ioana.ciornei@xxxxxxx>;
> netdev@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx; Voon, Weifeng
> <weifeng.voon@xxxxxxxxx>; vee.khee.wong@xxxxxxxxxxxxxxx; Wong, Vee Khee
> <vee.khee.wong@xxxxxxxxx>; Ismail, Mohammad Athari
> <mohammad.athari.ismail@xxxxxxxxx>
> Subject: Re: [PATCH net] net: phy: skip disabling interrupt when WOL is enabled
> in shutdown
> 
> On Tue, Jul 06, 2021 at 05:02:09PM +0800, Ling Pei Lee wrote:
> > From: Mohammad Athari Bin Ismail <mohammad.athari.ismail@xxxxxxxxx>
> >
> > PHY WOL requires WOL interrupt event to trigger the WOL signal in
> > order to wake up the system. Hence, the PHY driver should not disable
> > the interrupt during shutdown if PHY WOL is enabled.
> 
> If the device is being used to wake the system up, why is it being shutdown?
> 

Hi Andrew,

When the platform goes to S5 state (ex: shutdown -h now), regardless PHY WOL is enabled or not, phy_shutdown() is called. So, for the platform that support WOL from S5, we need to make sure the PHY still can trigger WOL event. Disabling the interrupt through phy_disable_interrupts() in phy_shutdown() will disable WOL interrupt as well and cause the PHY WOL not able to trigger.

-Athari-

> 	Andrew