Re: regression from: net: phy: marvell: Avoid unnecessary soft reset

From: Maxim Uvarov <muvarov@gmail.com>
To: Heiner Kallweit <hkallweit1@gmail.com>
Cc: liweihang <liweihang@hisilicon.com>,
	Florian Fainelli <f.fainelli@gmail.com>,
	Phil Reid <preid@electromag.com.au>,
	"netdev@vger.kernel.org" <netdev@vger.kernel.org>,
	Andrew Lunn <andrew@lunn.ch>,
	"David S. Miller" <davem@davemloft.net>,
	"dongsheng.wang@hxt-semitech.com"
	<dongsheng.wang@hxt-semitech.com>,
	"cphealy@gmail.com" <cphealy@gmail.com>,
	"clemens.gruber@pqgruber.com" <clemens.gruber@pqgruber.com>,
	"nbd@nbd.name" <nbd@nbd.name>,
	"harini.katakam@xilinx.com" <harini.katakam@xilinx.com>
Subject: Re: regression from: net: phy: marvell: Avoid unnecessary soft reset
Date: Wed, 20 Mar 2019 23:35:20 +0300	[thread overview]
Message-ID: <CAJGZr0LyYFLrqwL59ffCFm+fhf=R6Dki79ATMsLW+K+89PfxjQ@mail.gmail.com> (raw)
In-Reply-To: <416d3171-492d-2c9f-168a-88c5d2814db2@gmail.com>

also it's suspicions that in m88e1116r_config_init() delay is present
after first soft_reset() and missed after second.

Maxim.

ср, 20 мар. 2019 г. в 21:17, Heiner Kallweit <hkallweit1@gmail.com>:
>
> On 20.03.2019 13:22, liweihang wrote:
> >
> >
> >> -----Original Message-----
> >> From: Florian Fainelli [mailto:f.fainelli@gmail.com]
> >> Sent: Wednesday, March 20, 2019 11:37 AM
> >> To: liweihang <liweihang@hisilicon.com>; Phil Reid
> >> <preid@electromag.com.au>; netdev@vger.kernel.org
> >> Cc: Andrew Lunn <andrew@lunn.ch>; David S. Miller
> >> <davem@davemloft.net>; dongsheng.wang@hxt-semitech.com;
> >> cphealy@gmail.com; clemens.gruber@pqgruber.com; hkallweit1@gmail.com;
> >> nbd@nbd.name; harini.katakam@xilinx.com
> >> Subject: Re: regression from: net: phy: marvell: Avoid unnecessary soft reset
> >>
> >>
> >>
> >> On 3/19/2019 7:34 PM, liweihang wrote:
> >>> Hi all,
> >>>
> >>> I've met a similar issue and sent an email to discuss about it before:
> >>> Question about setting speed and duplex failed after auto-negotiation
> >>> disabled on marvell phy
> >>>
> >>> d6ab93364734 net: phy: marvell: Avoid unnecessary soft reset I
> >>> reverted this patch and the auto-negotiation works ok.
> >>>
> >>> Florian, could you please read my previous email and give me some advice?
> >>
> >> If you can copy the patch author on that email the next time that will help
> >> expedite things.
> >>
> >> So the problem seems to come from the fact that unless the BCMR_RESET bit
> >> is written, then m88e1121_config_aneg_rgmii_delays() has no effect, does
> >> that sound like what you are observing?
> >>
> >> Does the following work for you (Phil and yourself)?
> >
> > Thank you, Florian. But that didn't work for me either. I think the key question is
> > as what Heiner said, some bits need to be preserved.
> >
> > The MII_BMCR contained information of speed and duplex mode, but when we
> > call genphy_soft_reset(), these bits will be cleared.
> >
> I think instead of
>
> ret = phy_write(phydev, MII_BMCR, BMCR_RESET);
>
> we should use
>
> ret = phy_set_bits(phydev, MII_BMCR, BMCR_RESET);
>
> This is still in line with Clause 22 but covers more PHY's. A lot of PHY's
> won't be affected because they reset all BMCR bits to a default anyway.
> Could you please test this? If it's ok for you I'd submit a patch.
>
> >>
> >> diff --git a/drivers/net/phy/marvell.c b/drivers/net/phy/marvell.c index
> >> 3ccba37bd6dd..6a1ea4c2042a 100644
> >> --- a/drivers/net/phy/marvell.c
> >> +++ b/drivers/net/phy/marvell.c
> >> @@ -448,6 +448,10 @@ static int m88e1121_config_aneg(struct phy_device
> >> *phydev)
> >>                 err = m88e1121_config_aneg_rgmii_delays(phydev);
> >>                 if (err < 0)
> >>                         return err;
> >> +
> >> +               err = genphy_soft_reset(phydev);
> >> +               if (err < 0)
> >> +                       return err;
> >>         }
> >>
> >>         err = marvell_set_polarity(phydev, phydev->mdix_ctrl);
> >>
> >
>

-- 
Best regards,
Maxim Uvarov