linux-kernel - Re: [PATCH] net: phy: marvell: clear wol event before setting it

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Message-ID: <20180427152555.5e8efb9c@xhacker.debian>
Date:   Fri, 27 Apr 2018 15:25:55 +0800
From:   Jisheng Zhang <Jisheng.Zhang@...aptics.com>
To:     Bhadram Varka <vbhadram@...dia.com>
Cc:     Andrew Lunn <andrew@...n.ch>,
        Florian Fainelli <f.fainelli@...il.com>,
        "David S. Miller" <davem@...emloft.net>, <netdev@...r.kernel.org>,
        <linux-kernel@...r.kernel.org>,
        Jingju Hou <Jingju.Hou@...aptics.com>
Subject: Re: [PATCH] net: phy: marvell: clear wol event before setting it

On Thu, 26 Apr 2018 12:39:59 +0530 Bhadram Varka wrote:

> >>>>>
> >>>>> diff --git a/drivers/net/phy/marvell.c b/drivers/net/phy/marvell.c
> >>>>> index c22e8e383247..b6abe1cbc84b 100644
> >>>>> --- a/drivers/net/phy/marvell.c
> >>>>> +++ b/drivers/net/phy/marvell.c
> >>>>> @@ -115,6 +115,9 @@
> >>>>>    /* WOL Event Interrupt Enable */
> >>>>>    #define MII_88E1318S_PHY_CSIER_WOL_EIE BIT(7)
> >>>>>    +/* Copper Specific Interrupt Status Register */
> >>>>> +#define MII_88E1318S_PHY_CSISR                0x13
> >>>>> +
> >>>>>    /* LED Timer Control Register */
> >>>>>    #define MII_88E1318S_PHY_LED_TCR            0x12
> >>>>>    #define MII_88E1318S_PHY_LED_TCR_FORCE_INT BIT(15)
> >>>>> @@ -1393,6 +1396,12 @@ static int m88e1318_set_wol(struct 
> >>>>> phy_device *phydev,
> >>>>>            if (err < 0)
> >>>>>                goto error;
> >>>>>    +        /* If WOL event happened once, the LED[2] interrupt pin
> >>>>> +         * will not be cleared unless reading the CSISR register.
> >>>>> +         * So clear the WOL event first before enabling it.
> >>>>> +         */
> >>>>> +        phy_read(phydev, MII_88E1318S_PHY_CSISR);
> >>>>> +  
> >>>> Hi Jisheng
> >>>>
> >>>> The problem with this is, you could be clearing a real interrupt, link
> >>>> down/up etc. If interrupts are in use, i think the normal interrupt
> >>>> handling will clear the WOL interrupt? So can you make this read
> >>>> conditional on !phy_interrupt_is_valid()?  
> >>> So this will clear WoL interrupt bit from Copper Interrupt status 
> >>> register.
> >>>
> >>> How about clearing WoL status (Page 17, register 17) for every WOL 
> >>> event ?
> >>>  
> >> This is already properly done by setting 
> >> MII_88E1318S_PHY_WOL_CTRL_CLEAR_WOL_STATUS
> >> in m88e1318_set_wol()  
> > This part of the code executes only when we enable WOL through ethtool 
> > (ethtool -s eth0 wol g)
> >
> > Lets say once WOL enabled through magic packet - HW generates WOL 
> > interrupt once magic packet received.
> > The problem that I see here is that for the next immediate magic 
> > packet I don't see WOL interrupt generated by the HW.
> > I need to explicitly clear WOL status for HW to generate WOL interrupt.  
> 
> With the below patch I see WOL event interrupt for every magic packet 
> that HW receives...
> 
> diff --git a/drivers/net/phy/marvell.c b/drivers/net/phy/marvell.c
> index ed8a67d..5d3d138 100644
> --- a/drivers/net/phy/marvell.c
> +++ b/drivers/net/phy/marvell.c
> @@ -55,6 +55,7 @@
> 
>   #define MII_M1011_IEVENT               0x13
>   #define MII_M1011_IEVENT_CLEAR         0x0000
> +#define MII_M1011_IEVENT_WOL_EVENT     BIT(7)
> 
>   #define MII_M1011_IMASK                        0x12
> - #define MII_M1011_IMASK_INIT           0x6400
> + #define MII_M1011_IMASK_INIT           0x6480
> 
> @@ -195,13 +196,40 @@ struct marvell_priv {
>          bool copper;
>   };
> 
> +static int marvell_clear_wol_status(struct phy_device *phydev)
> +{
> +       int err, temp, oldpage;
> +
> +       oldpage = phy_read(phydev, MII_MARVELL_PHY_PAGE);
> +       if (oldpage < 0)
> +               return oldpage;
> +
> +       err = phy_write(phydev, MII_MARVELL_PHY_PAGE,
> +                        MII_88E1318S_PHY_WOL_PAGE);
> +       if (err < 0)
> +               return err;
> +
> +       /*
> +        * Clear WOL status so that for next WOL event
> +        * interrupt will be generated by HW
> +        */
> +       temp = phy_read(phydev, MII_88E1318S_PHY_WOL_CTRL);
> +       temp |= MII_88E1318S_PHY_WOL_CTRL_CLEAR_WOL_STATUS;
> +       err = phy_write(phydev, MII_88E1318S_PHY_WOL_CTRL, temp);

is it better to reuse __phy_write()?

> +       if (err < 0)
> +               return err;
> +
> +
> +       phy_write(phydev, MII_MARVELL_PHY_PAGE, oldpage);
> +
> +       return 0;
> +}
> +
>   static int marvell_ack_interrupt(struct phy_device *phydev)
>   {
>          int err;
> 
>          /* Clear the interrupts by reading the reg */
>          err = phy_read(phydev, MII_M1011_IEVENT);
> -
>          if (err < 0)
>                  return err;
> 
> @@ -1454,12 +1482,18 @@ static int marvell_aneg_done(struct phy_device 
> *phydev)
> 
>   static int m88e1121_did_interrupt(struct phy_device *phydev)
>   {
> -       int imask;
> +       int imask, err;
> 
>          imask = phy_read(phydev, MII_M1011_IEVENT);
> 
> -       if (imask & MII_M1011_IMASK_INIT)
> +       if (imask & MII_M1011_IMASK_INIT) {
> +               if (imask & MII_M1011_IEVENT_WOL_EVENT) {
> +                       err = marvell_clear_wol_status(phydev);
> +                       if (err < 0)
> +                               return 0;
> +               }
>                  return 1;
> +       }
> 
>          return 0;
>   }