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Date: Mon, 8 Apr 2019 09:47:02 +0200
From: Simon Horman <horms@...ge.net.au>
To: Heiner Kallweit <hkallweit1@...il.com>
Cc: Andrew Lunn <andrew@...n.ch>,
Florian Fainelli <f.fainelli@...il.com>,
David Miller <davem@...emloft.net>, netdev@...r.kernel.org,
linux-renesas-soc@...r.kernel.org
Subject: Re: [PATCH net-next] net: phy: fix autoneg mismatch case in
genphy_read_status
On Sun, Apr 07, 2019 at 05:09:28PM +0200, Heiner Kallweit wrote:
> On 05.04.2019 18:16, Simon Horman wrote:
> > On Tue, Apr 02, 2019 at 08:43:30PM +0200, Heiner Kallweit wrote:
> >> The original patch didn't consider the case that autoneg process
> >> finishes successfully but both link partners have no mode in common.
> >> In this case there's no link, nevertheless we may be interested in
> >> what the link partner advertised.
> >>
> >> Like phydev->link we set phydev->autoneg_complete in
> >> genphy_update_link() and use the stored value in genphy_read_status().
> >> This way we don't have to read register BMSR again.
> >>
> >> Fixes: b6163f194c69 ("net: phy: improve genphy_read_status")
> >> Signed-off-by: Heiner Kallweit <hkallweit1@...il.com>
> >
> > Hi,
> >
> > I have observed a regression with this patch as present as
> > 4950c2ba49cc ("net: phy: fix autoneg mismatch case in genphy_read_status")
> > in net-next.
> >
> > The platform is the Renesas R-Car E3 (r8a77990) based Ebisu-4D board.
> >
> >
> > Without this patch (commit before 4950c2ba49cc) the link is negotiated
> > as follows:
> >
> > [ 3.257699] libphy: ravb_mii: probed
> > [ 3.266498] ravb e6800000.ethernet eth0: Base address at 0xe6800000, 2e:09:0a:03:85:38, IRQ 104.
> > [ 3.537082] Micrel KSZ9031 Gigabit PHY e6800000.ethernet-ffffffff:00: attached PHY driver [Micrel KSZ9031 Gigabit PHY] (mii_bus:phy_addr=e6800000.ethernet-ffffffff:00, irq=165)
> > [ 9.667161] ravb e6800000.ethernet eth0: Link is Up - 1Gbps/Full - flow control off
> >
> > # ethtool --version
> > ethtool version 3.16
> > # ethtool eth0
> > Settings for eth0:
> > Supported ports: [ TP MII ]
> > Supported link modes: 100baseT/Full
> > 1000baseT/Full
> > Supported pause frame use: No
> > Supports auto-negotiation: Yes
> > Advertised link modes: 100baseT/Full
> > 1000baseT/Full
> > Advertised pause frame use: No
> > Advertised auto-negotiation: Yes
> > Link partner advertised link modes: 10baseT/Half 10baseT/Full
> > 100baseT/Half 100baseT/Full
> > 1000baseT/Full
> > Link partner advertised pause frame use: No
> > Link partner advertised auto-negotiation: Yes
> > Speed: 1000Mb/s
> > Duplex: Full
> > Port: MII
> > PHYAD: 0
> > Transceiver: external
> > Auto-negotiation: on
> > Supports Wake-on: g
> > Wake-on: d
> > Current message level: 0x000000cc (204)
> > link timer rx_err tx_err
> > Link detected: yes
> >
> >
> > With this patch the link is negotiated as follows, note the "Unknown":
> >
> > [ 3.268609] libphy: ravb_mii: probed
> > [ 3.277402] ravb e6800000.ethernet eth0: Base address at 0xe6800000, 2e:09:0a:03:85:38, IRQ 104.
> > [ 3.565057] Micrel KSZ9031 Gigabit PHY e6800000.ethernet-ffffffff:00: attached PHY driver [Micrel KSZ9031 Gigabit PHY] (mii_bus:phy_addr=e6800000.ethernet-ffffffff:00, irq=165)
> > [ 9.804423] ravb e6800000.ethernet eth0: Link is Up - Unknown/Unknown - flow control off
> >
> > And ethtool reports:
> >
> > # ethtool eth0
> > Settings for eth0:
> > Supported ports: [ TP MII ]
> > Supported link modes: 100baseT/Full
> > 1000baseT/Full
> > Supported pause frame use: No
> > Supports auto-negotiation: Yes
> > Advertised link modes: 100baseT/Full
> > 1000baseT/Full
> > Advertised pause frame use: No
> > Advertised auto-negotiation: Yes
> > Speed: Unknown!
> > Duplex: Unknown! (255)
> > Port: MII
> > PHYAD: 0
> > Transceiver: external
> > Auto-negotiation: on
> > Supports Wake-on: g
> > Wake-on: d
> > Current message level: 0x000000cc (204)
> > link timer rx_err tx_err
> > Link detected: yes
> >
> >
> >
> > I noticed this when preparing a patch limit the maximum speed the device to
> > 100Mbit/s as follows:
> >
> > --- a/arch/arm64/boot/dts/renesas/r8a77990-ebisu.dts
> > +++ b/arch/arm64/boot/dts/renesas/r8a77990-ebisu.dts
> > @@ -272,6 +272,7 @@
> > interrupt-parent = <&gpio2>;
> > interrupts = <21 IRQ_TYPE_LEVEL_LOW>;
> > reset-gpios = <&gpio1 20 GPIO_ACTIVE_LOW>;
> > + max-speed = <100>;
> > };
> > };
> >
> > While the 100Mbit/s limit applied on top of the commit before 4950c2ba49cc
> > things work as expected:
> >
> > [ 3.258347] libphy: ravb_mii: probed
> > [ 3.266739] ravb e6800000.ethernet eth0: Base address at 0xe6800000, 2e:09:0a:03:85:38, IRQ 104.
> > [ 3.553642] Micrel KSZ9031 Gigabit PHY e6800000.ethernet-ffffffff:00: attached PHY driver [Micrel KSZ9031 Gigabit PHY] (mii_bus:phy_addr=e6800000.ethernet-ffffffff:00, irq=165)
> > [ 5.585027] ravb e6800000.ethernet eth0: Link is Up - 100Mbps/Full - flow control off
> >
> > # ethtool eth0
> > Settings for eth0:
> > Supported ports: [ TP MII ]
> > Supported link modes: 100baseT/Full
> > Supported pause frame use: No
> > Supports auto-negotiation: Yes
> > Advertised link modes: 100baseT/Full
> > Advertised pause frame use: No
> > Advertised auto-negotiation: Yes
> > Link partner advertised link modes: 10baseT/Half 10baseT/Full
> > 100baseT/Half 100baseT/Full
> > Link partner advertised pause frame use: No
> > Link partner advertised auto-negotiation: Yes
> > Speed: 100Mb/s
> > Duplex: Full
> > Port: MII
> > PHYAD: 0
> > Transceiver: external
> > Auto-negotiation: on
> > Supports Wake-on: g
> > Wake-on: d
> > Current message level: 0x000000cc (204)
> > link timer rx_err tx_err
> > Link detected: yes
> >
> >
> > However, with the 100Mbit/s limit applied on top of 4950c2ba49cc the boot hangs
> > while (or just after?) negotiating the link:
> >
> > [ 3.541549] Micrel KSZ9031 Gigabit PHY e6800000.ethernet-ffffffff:00: attached PHY driver [Micrel KSZ9031 Gigabit PHY] (mii_bus:phy_addr=e6800000.ethernet-ffffffff:00, irq=165)
> > [ 5.536389] ravb e6800000.ethernet eth0: Link is Up - Unknown/Unknown - flow control off
> >
> >
>
> There's one path where phydev->autoneg_complete isn't set.
> Could you please test whether the following fixes the issue?
>
>
> diff --git a/drivers/net/phy/phy_device.c b/drivers/net/phy/phy_device.c
> index a6f3ad971..2df8f7737 100644
> --- a/drivers/net/phy/phy_device.c
> +++ b/drivers/net/phy/phy_device.c
> @@ -1710,19 +1710,17 @@ int genphy_update_link(struct phy_device *phydev)
> */
> if (!phy_polling_mode(phydev)) {
> status = phy_read(phydev, MII_BMSR);
> - if (status < 0) {
> + if (status < 0)
> return status;
> - } else if (status & BMSR_LSTATUS) {
> - phydev->link = 1;
> - return 0;
> - }
> + else if (status & BMSR_LSTATUS)
> + goto done;
> }
>
> /* Read link and autonegotiation status */
> status = phy_read(phydev, MII_BMSR);
> if (status < 0)
> return status;
> -
> +done:
> phydev->link = status & BMSR_LSTATUS ? 1 : 0;
> phydev->autoneg_complete = status & BMSR_ANEGCOMPLETE ? 1 : 0;
>
Thanks, that seems to resolve the problem I observed.
Using the same link partner as for the tests above I see:
* 4950c2ba49cc
+ fix (above)
+ patch to debug values of MII_BMSR in genphy_update_link()
# dmesg | egrep '(libphy|ravb|Micr)'
[ 2.028167] libphy: Fixed MDIO Bus: probed
[ 3.255678] ravb e6800000.ethernet: ignoring dependency for device, assuming no driver
[ 3.267865] libphy: ravb_mii: probed
[ 3.276210] ravb e6800000.ethernet eth0: Base address at 0xe6800000, 2e:09:0a:03:85:38, IRQ 104.
[ 3.563438] Micrel KSZ9031 Gigabit PHY e6800000.ethernet-ffffffff:00: attached PHY driver [Micrel KSZ9031 Gigabit PHY] (mii_bus:phy_addr=e6800000.ethernet-ffffffff:00, irq=165)
[ 3.581951] libphy: 1: MII_BMSR=0x00007949
[ 3.586439] libphy: 2: MII_BMSR=0x00007949
[ 9.985009] libphy: 1: MII_BMSR=0x0000796d
[ 9.990101] ravb e6800000.ethernet eth0: Link is Up - 1Gbps/Full - flow control off
# ethtool eth0
Settings for eth0:
Supported ports: [ TP MII ]
Supported link modes: 100baseT/Full
1000baseT/Full
Supported pause frame use: No
Supports auto-negotiation: Yes
Advertised link modes: 100baseT/Full
1000baseT/Full
Advertised pause frame use: No
Advertised auto-negotiation: Yes
Link partner advertised link modes: 10baseT/Half 10baseT/Full
100baseT/Half 100baseT/Full
1000baseT/Full
Link partner advertised pause frame use: No
Link partner advertised auto-negotiation: Yes
Speed: 1000Mb/s
Duplex: Full
Port: MII
PHYAD: 0
Transceiver: external
Auto-negotiation: on
Supports Wake-on: g
Wake-on: d
Current message level: 0x000000cc (204)
link timer rx_err tx_err
Link detected: yes
* 4950c2ba49cc
+ fix (above)
+ patch to debug values of MII_BMSR in genphy_update_link()
+ 100Mbit/s limit patch
# dmesg | egrep '(libphy|ravb|Micr)'
[ 2.026010] libphy: Fixed MDIO Bus: probed
[ 3.251741] ravb e6800000.ethernet: ignoring dependency for device, assuming no driver
[ 3.264054] libphy: ravb_mii: probed
[ 3.272573] ravb e6800000.ethernet eth0: Base address at 0xe6800000, 2e:09:0a:03:85:38, IRQ 104.
[ 3.559364] Micrel KSZ9031 Gigabit PHY e6800000.ethernet-ffffffff:00: attached PHY driver [Micrel KSZ9031 Gigabit PHY] (mii_bus:phy_addr=e6800000.ethernet-ffffffff:00, irq=165)
[ 3.577913] libphy: 1: MII_BMSR=0x00007949
[ 3.582407] libphy: 2: MII_BMSR=0x00007949
[ 5.663264] libphy: 1: MII_BMSR=0x0000796d
[ 5.668004] ravb e6800000.ethernet eth0: Link is Up - 100Mbps/Full - flow control off
# ethtool eth0
Settings for eth0:
Supported ports: [ TP MII ]
Supported link modes: 100baseT/Full
Supported pause frame use: No
Supports auto-negotiation: Yes
Advertised link modes: 100baseT/Full
Advertised pause frame use: No
Advertised auto-negotiation: Yes
Link partner advertised link modes: 10baseT/Half 10baseT/Full
100baseT/Half 100baseT/Full
Link partner advertised pause frame use: No
Link partner advertised auto-negotiation: Yes
Speed: 100Mb/s
Duplex: Full
Port: MII
PHYAD: 0
Transceiver: external
Auto-negotiation: on
Supports Wake-on: g
Wake-on: d
Current message level: 0x000000cc (204)
link timer rx_err tx_err
Link detected: yes
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