RE: [PATCH net-next V1 3/4] net: stmmac: Reconfigure the PHY WOL settings in stmmac_resume()

[Voon, Weifeng]

> > > > After PHY received a magic packet, the PHY WOL event will be
> > > > triggered then PHY WOL event interrupt will be disarmed.
> > > > Ethtool settings will remain with WOL enabled after a S3/S4
> > > > suspend resume cycle as expected. Hence,the driver should
> > > > reconfigure the PHY settings to reenable/disable WOL depending on
> > > > the ethtool WOL settings in the resume flow.
> > >
> > > Please could you explain this a bit more? I'm wondering if you have
> > > a PHY driver bug. PHY WOL should remain enabled until it is
> > > explicitly disabled.
> > >
> > > 	Andrew
> >
> > Let's take Marvell 1510 as example.
> >
> > As explained in driver/net/phy/marvell.c
> > 1773 >------->-------/* If WOL event happened once, the LED[2]
> > interrupt pin
> > 1774 >------->------- * will not be cleared unless we reading the
> > interrupt status
> > 1775 >------->------- * register.
> >
> > The WOL event will not able trigger again if the driver does not clear
> > the interrupt status.
> > Are we expecting PHY driver will automatically clears the interrupt
> > status rather than trigger from the MAC driver?
> 
> So you are saying the interrupt it getting discarded? I would of though it
> is this interrupt which brings to system out of suspend, and it should
> trigger the usual action, i.e. call the interrupt handler. That should then
> clear the interrupt.
> 
> 	 Andrew

No, the interrupt will not be discarded. If the PHY is in interrupt mode, the
interrupt handler will triggers and ISR will clear the WOL status bit. 
The condition here is when the PHY is in polling mode, the PHY driver does not
have any other mechanism to clear the WOL interrupt status bit.
Hence, we need to go through the PHY set_wol() again. 

Weifeng