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Date: Fri, 5 Apr 2019 18:16:28 +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 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
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