interface eth0 disappears after network cable unplug/re-plug

[Eric C.]

The following bug is reproducible with linux-image-3.13.0-53-generic, but not with linux-image-3.13.0-52-generic.

When I unplug the Ethernet cable from my laptop, I get the following messages in /var/log/kern.log after a few seconds (~20s):
May 22 13:59:36 host kernel: [ 5498.465626] pciehp 0000:00:1c.5:pcie04: Card not present on Slot(5)
May 22 13:59:36 host kernel: [ 5498.478755] pciehp 0000:00:1c.5:pcie04: Card present on Slot(5)
May 22 13:59:36 host kernel: [ 5498.598744] pciehp 0000:00:1c.5:pcie04: Device 0000:06:00.0 already exists at 0000:06:00, cannot hot-add
May 22 13:59:36 host kernel: [ 5498.598755] pciehp 0000:00:1c.5:pcie04: Cannot add device at 0000:06:00
May 22 13:59:36 host kernel: [ 5498.718646] atl1c 0000:06:00.0: MAC state machine can't be idle since disabled for 10ms second

Then, when I re-plug the cable, eth0 does not appear in network manager; there is no message in kern.log.
eth0 does not appear in ifconfig -a

$ ifconfig -a
lo Link encap:Local Loopback
          inet addr:127.0.0.1 Mask:255.0.0.0
          inet6 addr: ::1/128 Scope:Host
          UP LOOPBACK RUNNING MTU:65536 Metric:1
          RX packets:11586 errors:0 dropped:0 overruns:0 frame:0
          TX packets:11586 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:0
          RX bytes:16392353 (16.3 MB) TX bytes:16392353 (16.3 MB)

wlan0 Link encap:Ethernet HWaddr 48:5d:xx:xx:xx:xx
          inet addr:192.168.xx.xx Bcast:192.168.xx.xx Mask:255.255.255.0
          inet6 addr: fe80::xxxx:xxxx:xxxx:xxxx/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
          RX packets:19 errors:0 dropped:0 overruns:0 frame:0
          TX packets:66 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000
          RX bytes:2651 (2.6 KB) TX bytes:12364 (12.3 KB)

I tried to reinitialize networking with the following:
sudo modprobe -r atl1c
sudo modprobe atl1c

Still no eth0 and no message in kern.log

I tried
$ sudo ifup eth0
Ignoring unknown interface eth0=eth0.

Same symptoms occur when I reboot my router, and its Ethernet interface becomes temporarily unavailable.

Only way I found to restore eth0 was rebooting.
---
ApportVersion: 2.14.1-0ubuntu3.11
Architecture: amd64
AudioDevicesInUse:
 USER PID ACCESS COMMAND
 /dev/snd/controlC1: chewy 3002 F.... pulseaudio
 /dev/snd/controlC0: chewy 3002 F.... pulseaudio
CurrentDesktop: KDE
DistroRelease: Ubuntu 14.04
EcryptfsInUse: Yes
HibernationDevice: RESUME=UUID=17ba1751-f706-417b-ac40-1b4a7be825d8
InstallationDate: Installed on 2012-12-29 (873 days ago)
InstallationMedia: Kubuntu 12.04 LTS "Precise Pangolin" - Release amd64 (20120423)
MachineType: ASUSTeK Computer Inc. N53Jq
NonfreeKernelModules: nvidia
Package: linux (not installed)
ProcFB: 0 VESA VGA
ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-3.13.0-53-generic root=UUID=d48490d1-ca6a-448d-82e6-6397021cd403 ro quiet splash vt.handoff=7
ProcVersionSignature: Ubuntu 3.13.0-53.89-generic 3.13.11-ckt19
RelatedPackageVersions:
 linux-restricted-modules-3.13.0-53-generic N/A
 linux-backports-modules-3.13.0-53-generic N/A
 linux-firmware 1.127.12
Tags: trusty
Uname: Linux 3.13.0-53-generic x86_64
UpgradeStatus: Upgraded to trusty on 2014-09-05 (259 days ago)
UserGroups: adm admin cdrom dialout disk fuse lpadmin mediatomb plugdev sambashare vboxusers wireshark
_MarkForUpload: True
dmi.bios.date: 01/25/2011
dmi.bios.vendor: American Megatrends Inc.
dmi.bios.version: N53Jq.211
dmi.board.asset.tag: ATN12345678901234567
dmi.board.name: N53Jq
dmi.board.vendor: ASUSTeK Computer Inc.
dmi.board.version: 1.0
dmi.chassis.asset.tag: No Asset Tag
dmi.chassis.type: 10
dmi.chassis.vendor: ASUSTeK Computer Inc.
dmi.chassis.version: 1.0
dmi.modalias: dmi:bvnAmericanMegatrendsInc.:bvrN53Jq.211:bd01/25/2011:svnASUSTeKComputerInc.:pnN53Jq:pvr1.0:rvnASUSTeKComputerInc.:rnN53Jq:rvr1.0:cvnASUSTeKComputerInc.:ct10:cvr1.0:
dmi.product.name: N53Jq
dmi.product.version: 1.0
dmi.sys.vendor: ASUSTeK Computer Inc.

[Brad Figg (brad-figg)]

This bug is missing log files that will aid in diagnosing the problem. From a terminal window please run:

apport-collect 1457863

and then change the status of the bug to 'Confirmed'.

If, due to the nature of the issue you have encountered, you are unable to run this command, please add a comment stating that fact and change the bug status to 'Confirmed'.

This change has been made by an automated script, maintained by the Ubuntu Kernel Team.

[Eric C. (eric.c)]

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[Eric C. (eric.c)]

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[Eric C. (eric.c)]

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[Eric C. (eric.c)]

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[Eric C. (eric.c)]

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[Eric C. (eric.c)]

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[Eric C. (eric.c)]

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[Eric C. (eric.c)]

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[Eric C. (eric.c)]

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[Eric C. (eric.c)]

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[Eric C. (eric.c)]

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[Eric C. (eric.c)]

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[Eric C. (eric.c)]

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[Eric C. (eric.c)]

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[Eric C. (eric.c)]

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[Eric C. (eric.c)]

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[penalvch (penalvch)]

Eric Carlier, thank you for reporting this and helping make Ubuntu better. Could you please test the latest upstream kernel available from the very top line at the top of the page (the release names are irrelevant for testing, and please do not test the daily folder) following https://wiki.ubuntu.com/KernelMainlineBuilds ? It will allow additional upstream developers to examine the issue.

If the test did not allow you to test to the issue (ex. you couldn't boot into the OS) please make a comment in your report about this, and continue to test the next most recent kernel version until you can test to the issue. Once you've tested the upstream kernel, please comment on which kernel version specifically you tested. If this bug is fixed in the mainline kernel, please add the following tags by clicking on the yellow circle with a black pencil icon, next to the word Tags, located at the bottom of the report description:
kernel-fixed-upstream
kernel-fixed-upstream-X.Y-rcZ

Where XY and Z are numbers corresponding to the kernel version.

If the mainline kernel does not fix this bug, please add the following tags:
kernel-bug-exists-upstream
kernel-bug-exists-upstream-X.Y-rcZ

Once testing of the upstream kernel is complete, please mark this bug's Status as Confirmed. Please let us know your results.

Thank you for your understanding.

[Eric C. (eric.c)]

Tested upstream kernel 4.1-rc4 => fixed, with the following kern.log lines

May 23 14:27:49 host kernel: [ 188.368215] atl1c 0000:06:00.0: atl1c: eth0 NIC Link is Down
May 23 14:28:03 host kernel: [ 202.373866] pciehp 0000:00:1c.5:pcie04: Card not present on Slot(5)
May 23 14:28:03 host kernel: [ 202.373877] pciehp 0000:00:1c.5:pcie04: slot(5): Link Down event
May 23 14:28:03 host kernel: [ 202.373902] pciehp 0000:00:1c.5:pcie04: Link Down event ignored on slot(5): already powering off
May 23 14:28:03 host kernel: [ 202.378030] pciehp 0000:00:1c.5:pcie04: Card present on Slot(5)
May 23 14:28:03 host kernel: [ 202.378211] pciehp 0000:00:1c.5:pcie04: slot(5): Link Up event
May 23 14:28:03 host kernel: [ 202.378222] pciehp 0000:00:1c.5:pcie04: Link Up event ignored on slot(5): already powering on
May 23 14:28:03 host kernel: [ 202.626189] atl1c 0000:06:00.0: MAC state machine can't be idle since disabled for 10ms second
May 23 14:28:03 host kernel: [ 202.818099] pci 0000:06:00.0: [1969:1063] type 00 class 0x020000
May 23 14:28:03 host kernel: [ 202.818135] pci 0000:06:00.0: reg 0x10: [mem 0xd3200000-0xd323ffff 64bit]
May 23 14:28:03 host kernel: [ 202.818148] pci 0000:06:00.0: reg 0x18: [io 0x8000-0x807f]
May 23 14:28:03 host kernel: [ 202.818408] pci 0000:06:00.0: PME# supported from D0 D1 D2 D3hot D3cold
May 23 14:28:03 host kernel: [ 202.818454] pci 0000:06:00.0: System wakeup disabled by ACPI
May 23 14:28:03 host kernel: [ 202.826146] pci 0000:06:00.0: BAR 0: assigned [mem 0xd3200000-0xd323ffff 64bit]
May 23 14:28:03 host kernel: [ 202.826163] pci 0000:06:00.0: BAR 2: assigned [io 0x8000-0x807f]
May 23 14:28:03 host kernel: [ 202.826171] pcieport 0000:00:1c.5: PCI bridge to [bus 06]
May 23 14:28:03 host kernel: [ 202.826177] pcieport 0000:00:1c.5: bridge window [io 0x8000-0x8fff]
May 23 14:28:03 host kernel: [ 202.826185] pcieport 0000:00:1c.5: bridge window [mem 0xd3200000-0xd45fffff]
May 23 14:28:03 host kernel: [ 202.826197] pcieport 0000:00:1c.5: bridge window [mem 0xd9d00000-0xd9efffff 64bit pref]
May 23 14:28:03 host kernel: [ 202.826288] atl1c 0000:06:00.0: enabling device (0000 -> 0002)
May 23 14:28:03 host kernel: [ 202.826360] do_IRQ: 0.226 No irq handler for vector (irq -1)
May 23 14:28:03 host kernel: [ 202.854609] atl1c 0000:06:00.0: version 1.0.1.1-NAPI
May 23 14:28:03 host kernel: [ 202.874925] IPv6: ADDRCONF(NETDEV_UP): eth0: link is not ready
-> re-plug here
May 23 14:28:15 host kernel: [ 214.069310] atl1c 0000:06:00.0: atl1c: eth0 NIC Link is Up<100 Mbps Full Duplex>
May 23 14:28:15 host kernel: [ 214.069334] IPv6: ADDRCONF(NETDEV_CHANGE): eth0: link becomes ready

Tested upstream kernel 3.14.1-trusty => fixed, with the following kern.log lines
May 23 14:40:34 host kernel: [ 135.049761] atl1c 0000:06:00.0: atl1c: eth0 NIC Link is Down
-> re-plug here
May 23 14:41:35 host kernel: [ 195.412305] atl1c 0000:06:00.0: atl1c: eth0 NIC Link is Up<100 Mbps Full Duplex>

Tested upstream kernel 3.13.11.11-trusty => fixed, same verbosity as 3.14.1-trusty.

[penalvch (penalvch)]

Eric Carlier, the next step is to fully reverse commit bisect from kernel 3.13.11-ckt19 to 3.13.11.11 in order to identify the last bad commit, followed immediately by the first good one. Once this commit has been identified, then it may be reviewed as a candidate for backporting into your release. Could you please do this following https://wiki.ubuntu.com/Kernel/KernelBisection#How_do_I_reverse_bisect_the_upstream_kernel.3F ?

Please note, finding adjacent kernel versions is not fully commit bisecting.

Thank you for your understanding.

Helpful bug reporting tips:
https://wiki.ubuntu.com/ReportingBugs

[Eric C. (eric.c)]

Before trying to reverse commit bisect, I tried to boot on 3.13.11-ckt19. The problem is *not* present with this kernel. Only with 3.13.0-53 from Ubuntu packages.

[penalvch (penalvch)]

Eric Carlier, then it would appear the issue is due to a downstream only issue. Hence, let this be marked Triaged for now, and we may circle back on further testing as this report develops.

[Eric C. (eric.c)]

Some new elements: the bug seems to be linked with a KDE or X.org element. I tried the following:

Boot and login to the console => no bug (I can un/re-plug as much as I want)
Login to an X session => bug
Reboot
Login to an X session ; logout without trying to unplug.
Login to the console => no bug
Login to an X session => bug.

Note that in even when I login to the console, an X session is up with the greeter.

So it seems the problem only appears when a user is logged in an X session (only KDE Plasma desktop was tested).

[Eric C. (eric.c)]

The bug is not reproducible anymore, although no linux-* package was upgraded, and nothing kernel-related was changed on my machine.

[penalvch (penalvch)]

Eric Carlier, this bug report is being closed due to your last comment https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1457863/comments/24 regarding this is no longer reproducible. For future reference you can manage the status of your own bugs by clicking on the current status in the yellow line and then choosing a new status in the revealed drop down box. You can learn more about bug statuses at https://wiki.ubuntu.com/Bugs/Status. Thank you again for taking the time to report this bug and helping to make Ubuntu better. Please submit any future bugs you may find.