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

[Bhadram Varka]

Hi,
On 4/26/2018 11:45 AM, Jisheng Zhang wrote:
> Hi,
>
> On Thu, 26 Apr 2018 11:10:21 +0530 Bhadram Varka wrote:
>
> > Hi,
> >
> > On 4/19/2018 5:48 PM, Andrew Lunn wrote:
> > > On Thu, Apr 19, 2018 at 04:02:32PM +0800, Jisheng Zhang wrote:
> > > > From: Jingju Hou <Jingju.Hou@xxxxxxxxxxxxx>
> > > >
> > > > If WOL event happened once, the LED[2] interrupt pin will not be
> > > > cleared unless reading the CSISR register. So clear the WOL event
> > > > before enabling it.
> > > >
> > > > Signed-off-by: Jingju Hou <Jingju.Hou@xxxxxxxxxxxxx>
> > > > Signed-off-by: Jisheng Zhang <Jisheng.Zhang@xxxxxxxxxxxxx>
> > > > ---
> > > >    drivers/net/phy/marvell.c | 9 +++++++++
> > > >    1 file changed, 9 insertions(+)
> > > >
> > > > 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.