Hotplug remove and re-add adds PCI adapter to next PCI domain (PCI)

[bugproxy]

== Comment: #26 - Guilherme Guaglianoni Piccoli <email address hidden> - 2016-07-15 16:26:38 ==
When performing hotplug operations in PowerPC currently, if we remove a PHB and re-add it later, its domain address is incremented. An example below (drmgr is the tool we use in PowerPC to perform this operation):

(i) $> lspci
0000:60:00.0 Ethernet controller: Broadcom Corporation NetXtreme II BCM57810 10 Gigabit Ethernet
0000:60:00.1 Ethernet controller: Broadcom Corporation NetXtreme II BCM57810 10 Gigabit Ethernet

(ii) $> drmgr -c phb -s "PHB 20" -r # removing a PHB

(iii) $> lspci #empty

(iv) $> drmgr -c phb -s "PHB 20" -a # re-adding the PHB

(v) $> lspci
0001:60:00.0 Ethernet controller: Broadcom Corporation NetXtreme II BCM57810 10 Gigabit Ethernet
0001:60:00.1 Ethernet controller: Broadcom Corporation NetXtreme II BCM57810 10 Gigabit Ethernet

This behavior is harmful when kernel is using network predictable naming for interfaces, for example, since after the PHB re-add, the PCI address of NIC functions changes, and so the interfaces' naming also change. Recently, a patch was merged to powerpc-next to avoid this situation, by relating the PCI domain number with device-tree properties. With the patch, the above steps (i) and (v) present the same output for lspci.

We want to ask Canonical to merge the patch in Ubuntu Xenial's kernel, since it will solve multiple bugs we've experienced by performing NIC hotplug - the commit is present on powerpc-next under the commit-id 63a72284b15.

A link to the patch: https://git.kernel.org/cgit/linux/kernel/git/powerpc/linux.git/commit/?id=63a72284b159c569ec52f380c9

Thanks in advance,

Guilherme

[bugproxy (bugproxy)]

------- Comment From <email address hidden> 2016-07-15 18:14 EDT-------
FYI Canonical: This is an updated and upstream patch to address the issue originally documented in LP Bug 1560514.

[Tim Gardner (timg-tpi)]

https://lists.ubuntu.com/archives/kernel-team/2016-July/079182.html

[Stefan Bader (smb)]

This bug is awaiting verification that the kernel in -proposed solves the problem. Please test the kernel and update this bug with the results. If the problem is solved, change the tag 'verification-needed-xenial' to 'verification-done-xenial'.

If verification is not done by 5 working days from today, this fix will be dropped from the source code, and this bug will be closed.

See https://wiki.ubuntu.com/Testing/EnableProposed for documentation how to enable and use -proposed. Thank you!

[bugproxy (bugproxy)]

------- Comment From <email address hidden> 2016-08-16 16:09 EDT-------
Checked on proposed kernel 4.4.0-36 and everything is working fine.
Marking as "verification-done-xenial".

Cheers,

Guilherme

[Launchpad Janitor (janitor)]

This bug was fixed in the package linux - 4.4.0-36.55

---------------
linux (4.4.0-36.55) xenial; urgency=low

  [ Stefan Bader ]

  * Release Tracking Bug
    - LP: #1612305

  * I2C touchpad does not work on AMD platform (LP: #1612006)
    - SAUCE: pinctrl/amd: Remove the default de-bounce time

  * CVE-2016-5696
    - tcp: make challenge acks less predictable

linux (4.4.0-35.54) xenial; urgency=low

  [ Stefan Bader ]

  * Release Tracking Bug
    - LP: #1611215

  * [i915_bpo] Sync with v4.7 (LP: #1609742)
    - SAUCE: i915_bpo: Sync with v4.7

  * s390/cio: fix reset of channel measurement block (LP: #1609415)
    - s390/cio: allow to reset channel measurement block

  * in Ubuntu16.10: Hit on Call traces and system goes down when transactional
    memory tests are running in 32TB Brazos system (LP: #1606786)
    - powerpc/tm: Avoid SLB faults in treclaim/trecheckpoint when RI=0
    - powerpc/tm: Fix stack pointer corruption in __tm_recheckpoint()

  * Power Menu does not display after press the Power Button (LP: #1609204)
    - intel-vbtn: new driver for Intel Virtual Button
    - [config] enable CONFIG_INTEL_VBTN=m

  * OptiPlex 7450 AIO hangs when rebooting (LP: #1608762)
    - x86/reboot: Add Dell Optiplex 7450 AIO reboot quirk

  * virtualbox+usb 3.0 breaks boot, -28 kernel works (LP: #1604058)
    - SAUCE: xhci: Fix soft lockup in xhci_pci_probe path when XHCI_STATE_HALTED

  * linux-kernel: Freeing IRQ from IRQ context (LP: #1597908)
    - block: defer timeouts to a workqueue

  * Tunnel offload indications not stripped from encapsulated packets, causing
    performance overhead (LP: #1602755)
    - tunnels: Remove encapsulation offloads on decap.

  * lm-sensors is throwing "ERROR: Can't get value of subfeature temp1_input:
    I/O error" for be2net driver (LP: #1607387)
    - be2net: perform temperature query in adapter regardless of its interface
      state

  * Dell dock MAC Address pass through doesn't work in Ubuntu (LP: #1579984)
    - r8152: Add support for setting pass through MAC address on RTL8153-AD

  * vmxnet3 LRO IPv6 performance issues (stalling TCP) (LP: #1605494)
    - Driver: Vmxnet3: set CHECKSUM_UNNECESSARY for IPv6 packets

  * ISST-LTE:pVM:monklp5:Ubuntu16.04.1:system crashed at
    lpfc_sli4_scmd_to_wqidx_distr (LP: #1597974)
    - SAUCE: lpfc: fix oops in lpfc_sli4_scmd_to_wqidx_distr() from
      lpfc_send_taskmgmt()

  * Backport cxlflash shutdown patch to Xenial SRU (LP: #1605405)
    - SAUCE: cxlflash: Verify problem state area is mapped before notifying
      shutdown

  * Xenial update to v4.4.16 stable release (LP: #1607404)
    - mac80211: fix fast_tx header alignment
    - mac80211: mesh: flush mesh paths unconditionally
    - mac80211_hwsim: Add missing check for HWSIM_ATTR_SIGNAL
    - mac80211: Fix mesh estab_plinks counting in STA removal case
    - EDAC, sb_edac: Fix rank lookup on Broadwell
    - IB/cm: Fix a recently introduced locking bug
    - IB/mlx4: Properly initialize GRH TClass and FlowLabel in AHs
    - powerpc/pseries: Fix IBM_ARCH_VEC_NRCORES_OFFSET since POWER8NVL was added
    - powerpc/tm: Always reclaim in start_thread() for exec() class syscalls
    - usb: dwc2: fix reg...

[Andy Whitcroft (apw)]

This bug was nominated against a series that is no longer supported, ie yakkety. The bug task representing the yakkety nomination is being closed as Won't Fix.

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