RE: [PATCH V3 net] net: stmmac: fix MAC WoL unwork if PHY doesn't support WoL

[Joakim Zhang <qiangqing.zhang@nxp.com>]

> -----Original Message-----
> From: Florian Fainelli <f.fainelli@gmail.com>
> Sent: 2021年4月29日 0:22
> To: Andrew Lunn <andrew@lunn.ch>; Joakim Zhang
> <qiangqing.zhang@nxp.com>
> Cc: peppe.cavallaro@st.com; alexandre.torgue@st.com;
> joabreu@synopsys.com; davem@davemloft.net; kuba@kernel.org;
> Jisheng.Zhang@synaptics.com; netdev@vger.kernel.org; dl-linux-imx
> <linux-imx@nxp.com>
> Subject: Re: [PATCH V3 net] net: stmmac: fix MAC WoL unwork if PHY doesn't
> support WoL
> 
> 
> 
> On 4/28/2021 5:26 AM, Andrew Lunn wrote:
> >>  static int stmmac_set_wol(struct net_device *dev, struct
> >> ethtool_wolinfo *wol)  {
> >>  	struct stmmac_priv *priv = netdev_priv(dev);
> >> -	u32 support = WAKE_MAGIC | WAKE_UCAST;
> >> +	struct ethtool_wolinfo wol_phy = { .cmd = ETHTOOL_GWOL };
> >> +	u32 support = WAKE_MAGIC | WAKE_UCAST | WAKE_MAGICSECURE |
> >> +WAKE_BCAST;
> >
> > Reverse christmass tree please.
> >
> >>
> >> -	if (!device_can_wakeup(priv->device))
> >> -		return -EOPNOTSUPP;
> >> +	if (wol->wolopts & ~support)
> >> +		return -EINVAL;
> >
> > Maybe -EOPNOTSUPP would be better.
> >
> >>
> >> -	if (!priv->plat->pmt) {
> >> +	/* First check if can WoL from PHY */
> >> +	phylink_ethtool_get_wol(priv->phylink, &wol_phy);
> >
> > This could return an error. In which case, you probably should not
> > trust wol_phy.
> >
> >> +	if (wol->wolopts & wol_phy.supported) {
> >
> > This returns true if the PHY supports one or more of the requested WoL
> > sources.
> >
> >>  		int ret = phylink_ethtool_set_wol(priv->phylink, wol);
> >
> > and here you request the PHY to enable all the requested WoL sources.
> > If it only supports a subset, it is likely to return -EOPNOTSUPP, or
> > -EINVAL, and do nothing. So here you only want to enable those sources
> > the PHY actually supports. And let the MAC implement the rest.
> 
> And when your resubmit, I do not believe that unwork is a word, you could
> provide the following subject:
> 
> net: stmmac: Fix MAC WoL not working if PHY does not support WoL
> 
> or something like that.

Ok, thanks Florian!

Best Regards,
Joakim Zhang
> Thanks!
> --
> Florian