Re: net: stmmac: dwmac-rk: fixes for Wake-on-Lan on RK3288

[Giuseppe CAVALLARO]

On 6/16/2016 4:51 PM, Vincent Palatin wrote:
> Hi Giuseppe,
>
> On Thu, Jun 16, 2016 at 6:37 AM, Giuseppe CAVALLARO
> <peppe.cavallaro@xxxxxx> wrote:
> > Hi Vincent
> >
> >
> > On 6/15/2016 7:04 PM, Vincent Palatin wrote:
> > > On Sun, Jun 12, 2016 at 11:46 PM, Giuseppe CAVALLARO
> > > <peppe.cavallaro@xxxxxx> wrote:
> > > > On 6/11/2016 3:00 AM, Vincent Palatin wrote:
> > > > > In order to support Wake-On-Lan when using the RK3288 integrated MAC
> > > > > (with an external RGMII PHY), we need to avoid shutting down the regulator
> > > > > of the external PHY when the MAC is suspended as it's currently done in
> > > > > the MAC
> > > > > platform code.
> > > > > As a first step, create independant callbacks for suspend/resume rather
> > > > > than
> > > > > re-using exit/init callbacks. So the dwmac platform driver can behave
> > > > > differently
> > > > > on suspend where it might skip shutting the PHY and at module unloading.
> > > > > Then update the dwmac-rk driver to switch off the PHY regulator only if we
> > > > > are
> > > > > not planning to wake up from the LAN.
> > > > > Finally add the PMT interrupt to the MAC device tree configuration, so we
> > > > > can
> > > > > wake up the core from it when the PHY has received the magic packet.
> > > >
> > > >
> > > >
> > > > IMO these could be sent for net-next and also other glue logic
> > > > files should be reworked in order to use the new API for coherence.
> > >
> > >
> > > Given they will have the same set of functions for exit/init and
> > > suspend/resume, you mean duplicating the callbacks like this :
> > > --- a/drivers/net/ethernet/stmicro/stmmac/dwmac-sti.c
> > > +++ b/drivers/net/ethernet/stmicro/stmmac/dwmac-sti.c
> > > @@ -359,6 +359,8 @@ static int sti_dwmac_probe(struct platform_device *pdev)
> > >         plat_dat->bsp_priv = dwmac;
> > >         plat_dat->init = sti_dwmac_init;
> > >         plat_dat->exit = sti_dwmac_exit;
> > > +       plat_dat->suspend = sti_dwmac_exit;
> > > +       plat_dat->resume = sti_dwmac_init;
> > >         plat_dat->fix_mac_speed = data->fix_retime_src;
> > >
> > >         ret = sti_dwmac_init(pdev, plat_dat->bsp_priv);
> > >
> > > Is this anyhow useful ?
> >
> >
> > I think this is mandatory otherwise you are not guaranteeing the PM
> > stuff working on the rest of the glue-logics (not only sti); because
> > init/exit calls won't be called anymore.
>
>
> As mentioned in the PATCH 1/3 description: "If the driver does not
> provide the suspend or resume callback, we fall
> back to the old behavior trying to use exit or init. [...]"
> ie.
> --- a/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c
> +++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c
> @@ -411,7 +411,9 @@ static int stmmac_pltfr_suspend(struct device *dev)
>         struct platform_device *pdev = to_platform_device(dev);
>
>         ret = stmmac_suspend(dev);
> -       if (priv->plat->exit)
> +       if (priv->plat->suspend)
> +               priv->plat->suspend(pdev, priv->plat->bsp_priv);
> +       else if (priv->plat->exit)
>                 priv->plat->exit(pdev, priv->plat->bsp_priv);
>
>         return ret;
> @@ -430,7 +432,9 @@ static int stmmac_pltfr_resume(struct device *dev)
>         struct stmmac_priv *priv = netdev_priv(ndev);
>         struct platform_device *pdev = to_platform_device(dev);
>
> -       if (priv->plat->init)
> +       if (priv->plat->resume)
> +               priv->plat->resume(pdev, priv->plat->bsp_priv);
> +       else if (priv->plat->init)
>                 priv->plat->init(pdev, priv->plat->bsp_priv);
>
>         return stmmac_resume(dev);
>
> So I was under the impression that everything should continue working
> as before for drivers only providing init/exit,
> by falling back on calling ->exit() if there is no suspend() callback
> initialized for the PM calls.
> You think that won't work ?

it's ok for me.

Peppe

> > So I kindly ask you to
> > propagate the fix and send the V3.  The implementation above is ok for
> > me.
> >
> > peppe