Re: i.MX28 based system losing eth0 on boot

[Brian Lilly]

It would appear that I don't have that commit.  I could move to 3.14
to see if it makes a difference, but the last couple of responses have
been on 3.12.18 -- or perhaps I'm missing something else.
Please let me know if you have any questions.

Thank you.

Brian Lilly
Crystalfontz America, Incorporated
12412 East Saltese Road
Spokane Valley, WA 99216
brian@xxxxxxxxxxxxxxxx http://www.crystalfontz.com
Twitter: @Crystalfontz
US toll-free (888) 206-9720 voice (509) 892-1200


On Tue, May 6, 2014 at 3:06 PM, Florian Fainelli <f.fainelli@xxxxxxxxx> wrote:
> 2014-05-06 14:40 GMT-07:00 Brian Lilly <brian@xxxxxxxxxxxxxxxx>:
>> The PHY on board is the SMSC LAN8720
>>
>> With the generic PHY driver selected:  http://pastebin.com/A4MH4Ptw
>>
>> [   28.828761] fec 800f0000.ethernet eth0: Freescale FEC PHY driver
>> [Generic PHY] (mii_bus:phy_addr=800f0000.etherne:00, irq=-1)
>> [   28.840626] IPv6: ADDRCONF(NETDEV_UP): eth0: link is not ready
>> [   30.827536] libphy: 800f0000.etherne:00 - Link is Up - 100/Full
>> [   30.833739] IPv6: ADDRCONF(NETDEV_CHANGE): eth0: link becomes ready
>> [   32.986999] IPv6: ADDRCONF(NETDEV_UP): usb0: link is not ready
>> [   37.316421] fec 800f0000.ethernet eth0: Freescale FEC PHY driver
>> [Generic PHY] (mii_bus:phy_addr=800f0000.etherne:00, irq=-1)
>> [   38.345047] fec 800f0000.ethernet eth0: MDIO read timeout
>> [   39.506210] IPv6: ADDRCONF(NETDEV_UP): eth0: link is not ready
>> [   40.374961] fec 800f0000.ethernet eth0: MDIO read timeout
>>
>> With the SMSC PHY driver selected:  http://pastebin.com/DhdDyrMv
>>
>> [   28.778974] fec 800f0000.ethernet eth0: Freescale FEC PHY driver
>> [SMSC LAN8710/LAN8720] (mii_bus:phy_addr=800f0000.etherne:00, irq=-1)
>> [   28.791742] IPv6: ADDRCONF(NETDEV_UP): eth0: link is not ready
>> [   30.773078] libphy: 800f0000.etherne:00 - Link is Up - 100/Full
>> [   30.779286] IPv6: ADDRCONF(NETDEV_CHANGE): eth0: link becomes ready
>> [   32.934692] IPv6: ADDRCONF(NETDEV_UP): usb0: link is not ready
>> [   37.242162] fec 800f0000.ethernet eth0: Freescale FEC PHY driver
>> [SMSC LAN8710/LAN8720] (mii_bus:phy_addr=800f0000.etherne:00, irq=-1)
>> [   38.270611] fec 800f0000.ethernet eth0: MDIO read timeout
>> [   39.415256] IPv6: ADDRCONF(NETDEV_UP): eth0: link is not ready
>> [   40.300454] fec 800f0000.ethernet eth0: MDIO read timeout
>
> Thanks for trying this, at least this is consistent no matter which
> PHY driver we are using. Just to rule out a potential PHY power-down
> issue, could you try to revert the following commit
> be9dad1f9f26604fb71c0d53ccb39a8f1d425807 ("net: phy: suspend phydev
> when going to HALTED") and see if that works better for you?
>
> Thanks!
>
>>
>> On Tue, May 6, 2014 at 12:24 PM, Florian Fainelli <f.fainelli@xxxxxxxxx> wrote:
>>> 2014-05-06 12:12 GMT-07:00 Brian Lilly <brian@xxxxxxxxxxxxxxxx>:
>>>> It is happening during boot up:
>>>>
>>>> <snip, kernel 3.12 >
>>>>
>>>> Configuring network interfaces... [   35.117114] fec 800f0000.ethernet
>>>> eth0: Freescale FEC PHY driver [SMSC LAN8710/LAN8720]
>>>
>>> Note that the SMSC PHY driver is picked up here, and that specific
>>> driver implements a different phy_read_status() callback due to how
>>> the PHY operates. The PHY driver also overrides the config_init()
>>> callback to perform some PHY-specific initialization. See below for
>>> more.
>>>
>>>> (mii_bus:phy_addr=800f0000.etherne:00, irq=-1)
>>>> [   35.129967] IPv6: ADDRCONF(NETDEV_UP): eth0: link is not ready
>>>> udhcpc (v1.21.1) started
>>>>
>>>> Sending discover...
>>>>
>>>> [   37.113901] libphy: 800f0000.etherne:00 - Link is Up - 100/Full
>>>> [   37.120134] IPv6: ADDRCONF(NETDEV_CHANGE): eth0: link becomes ready
>>>> Sending discover...
>>>>
>>>> Sending select for 10.10.10.217...
>>>> Lease of 10.10.10.217 obtained, lease time 86400
>>>> /etc/udhcpc.d/50default: Adding DNS 10.10.10.13
>>>> [   39.319957] IPv6: ADDRCONF(NETDEV_UP): usb0: link is not ready
>>>> done.
>>>> Starting rpcbind daemon...done.
>>>> net.ipv4.conf.default.rp_filter = 1
>>>> net.ipv4.conf.all.rp_filter = 1
>>>> Mon Apr 14 22:40:00 UTC 2014
>>>> INIT: Entering runlevel: 5
>>>> Starting Xserver
>>>> Starting system message bus: dbus.
>>>> Starting Connection Manager
>>>> Starting wpa_supplicant
>>>> Successfully initialized wpa_supplicant
>>>> Starting Dropbear SSH server
>>>> [   44.754915] fec 800f0000.ethernet eth0: Freescale FEC PHY driver
>>>> [SMSC LAN8710/LAN8720] (mii_bus:phy_addr=800f0000.etherne:00, irq=-1)
>>>
>>> The correct PHY driver is selected here...
>>>
>>>> [   45.781364] fec 800f0000.ethernet eth0: MDIO read timeout
>>>> [   46.826170] IPv6: ADDRCONF(NETDEV_UP): eth0: link is not ready
>>>> [   47.811385] fec 800f0000.ethernet eth0: MDIO read timeout
>>>
>>> But we are still seeing MDIO read timeouts, which is not great.
>>>
>>>>
>>>> With a different kernel (3.14):
>>>>
>>>> [   28.989897] fec 800f0000.ethernet eth0: Freescale FEC PHY driver
>>>> [Generic PHY] (mii_bus:phy_addr=800f0000.etherne:00, irq=-1)
>>>> [   30.991210] libphy: 800f0000.etherne:00 - Link is Up - 100/Full
>>>> [   37.369372] fec 800f0000.ethernet eth0: Freescale FEC PHY driver
>>>> [Generic PHY] (mii_bus:phy_addr=800f0000.etherne:00, irq=-1)
>>>
>>> Here, the Generic PHY driver has been selected, which will use the
>>> MII_BMSR register contents to determine the Link status and
>>> parameters. You might want to make sure that your board selects the
>>> appropriate PHY driver, such that we are not chasing two issues here.
>>>
>>>> [   38.398346] fec 800f0000.ethernet eth0: MDIO read timeout
>>>> [   39.438412] fec 800f0000.ethernet eth0: MDIO read timeout
>>>> [   39.468419] fec 800f0000.ethernet eth0: MDIO write timeout
>>>> [   40.498848] fec 800f0000.ethernet eth0: MDIO read timeout
>>>
>>> It would also be helpful to print the register that were accessed,
>>> such that you could correlate this with the exact steps in the PHY
>>> library state machine. Please also retry the experiment with the SMSC
>>> PHY driver enabled, as it does some PHY specific initialization that
>>> seems to be relevant. Then we are hopefully left with only the MDIO
>>> timeout issue and not the PHY mis-configuration + MDIO timeout.
>>>
>>>>
>>>> Afterward I have to ifdown eth0, ifup eth0 and then it functions
>>>> normally, without reverting the commit.
>>>>
>>>> root@cfa100xx:~# ifdown eth0
>>>> [ 1154.679658] fec 800f0000.ethernet eth0: Freescale FEC PHY driver
>>>> [Generic PHY] (mii_bus:phy_addr=800f0000.etherne:00, irq=-1)
>>>> root@cfa100xx:~# ifup eth0
>>>> udhcpc (v1.21.1) started
>>>> Sending discover...
>>>> [ 1156.679547] libphy: 800f0000.etherne:00 - Link is Up - 100/Full
>>>> Sending discover...
>>>> Sending select for 10.10.10.217...
>>>> Lease of 10.10.10.217 obtained, lease time 86400
>>>> ip: RTNETLINK answers: File exists
>>>>
>>>> --
>>>> Brian
>>>>
>>>>
>>>> On Tue, May 6, 2014 at 11:11 AM, Uwe Kleine-KÃnig
>>>> <u.kleine-koenig@xxxxxxxxxxxxxx> wrote:
>>>>> Hello Brian,
>>>>>
>>>>> On Tue, May 06, 2014 at 09:44:34AM -0700, Brian Lilly wrote:
>>>>>> With commit a264b981f2c76e281ef27e7232774bf6c54ec865 we're having eth0
>>>>>> come up, then brought right back down with an MDIO rx timeout moments
>>>>>> after.  Adding back in the removed code keeps the interface alive and
>>>>>> it's working afterward without trouble.  I've tested the re-inserted
>>>>>> code in 3.12, 3.14 without issue on our boards.
>>>>> So you can reliably trigger that problem? You're just doing
>>>>>
>>>>>         ifconfig eth0 1.2.3.4 up
>>>>>
>>>>> (or equivalent) and the interface goes down without further
>>>>> interference with the above mentioned commit? The exact error you're
>>>>> seeing is
>>>>>
>>>>>         MDIO read timeout
>>>>>
>>>>> (with some prefix saying something about fec and eth0 I think)?
>>>>>
>>>>> This error is also present with a264b981f2 reverted, just doesn't affect
>>>>> eth0 being functional? Does the timeout always happen, or only on
>>>>> specific addresses?
>>>>>
>>>>> This is not a proper fix, but does it help to increment FEC_MII_TIMEOUT?
>>>>>
>>>>>> Is there something else that can be done to prevent the MDIO timeouts?
>>>>>> We are using basically the same schematic for networking as the
>>>>>> imx28evk.
>>>>> Hard to say, but assuming it works just fine on the imx28evk for you,
>>>>> too, there seems to be some hardware difference that makes your machine
>>>>> fail. (That doesn't mean it's not fixable in software.)
>>>>>
>>>>> I don't know if a mdio read error is intended to make the device go
>>>>> down, maybe one the the netdev guys can answer that.
>>>>> Assuming that it's not intended, instrument the code, find out how that
>>>>> timeout makes your device go down and find the wrong branch. I'd start
>>>>> with adding stackdumps when the mdio timeout happens and when
>>>>> fec_enet_start_xmit is called with fep->link == 0.
>>>>>
>>>>> Best regards
>>>>> Uwe
>>>>>
>>>>> --
>>>>> Pengutronix e.K.                           | Uwe Kleine-KÃnig            |
>>>>> Industrial Linux Solutions                 | http://www.pengutronix.de/  |
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>>>
>>>
>>>
>>> --
>>> Florian
>
>
>
> --
> Florian
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