Support for TI Message Manager Module. This hardware block manages a
bunch of hardware queues meant for communication between processor
entities.

Clients sitting on top of this would manage the required protocol
for communicating with the counterpart entities.

For more details on TI Message Manager hardware block, see documentation
that will is available here: http://www.ti.com/lit/ug/spruhy8/spruhy8.pdf
Chapter 8.1(Message Manager)
Signed-off-by: Nishanth Menon <nm@ti.com>
Signed-off-by: Jassi Brar <jaswinder.singh@linaro.org>

Message Manager is a hardware block used to communicate with various
processor systems within certain Texas Instrument's Keystone
generation SoCs.

This hardware engine is used to transfer messages from various compute
entities(or processors) within the SoC. It is designed to be self
contained without needing software initialization for operation.
Signed-off-by: Nishanth Menon <nm@ti.com>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Jassi Brar <jaswinder.singh@linaro.org>

The newly added rockchip mailbox driver causes a bug in
the ARM allyesconfig build because of a division of a resource_size_t
variable that may be 64 bit wide:

drivers/mailbox/built-in.o: In function `rockchip_mbox_probe':
:(.text+0x6614): undefined reference to `__aeabi_uldivmod'

This adds a cast to size_t, which turns it into a 32-bit division
in this case. This is safe because we know that we cannot possibly
map a resource that is longer than what a pointer contains, and
in practice it will be very short instead.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Jassi Brar <jaswinder.singh@linaro.org>

This driver is found on RK3368 SoCs.

The Mailbox module is a simple APB peripheral that allows both
the Cortex-A53 MCU system to communicate by writing operation to
generate interrupt.
The registers are accessible by both CPU via APB interface.

The Mailbox has the following main features:

1) Support dual-core system: Cortex-A53 and MCU.
2) Support APB interface.
3) Support four mailbox elements, each element includes one data word,
   one command word register and one flag bit that can represent
   one interrupt.
4) Four interrupts to Cortex-A53.
5) Four interrupts to MCU.
6) Provide 32 lock registers for software to use to indicate whether
   mailbox is occupied.

[Jassi: Removed unused variable buf_base]
Signed-off-by: Caesar Wang <wxt@rock-chips.com>
Signed-off-by: Jassi Brar <jaswinder.singh@linaro.org>

This add the necessary binding documentation for mailbox
found on RK3368 SoC.
Signed-off-by: Caesar Wang <wxt@rock-chips.com>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Jassi Brar <jaswinder.singh@linaro.org>

devm_ioremap() returns NULL, it never returns an ERR_PTR.

Fixes: f700e84f ('mailbox: Add support for APM X-Gene platform mailbox driver')
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Jassi Brar <jaswinder.singh@linaro.org>

Add driver for Hi6220 mailbox, the mailbox communicates with MCU; for
sending data, it can support two methods for low level implementation:
one is to use interrupt as acknowledge, another is automatic mode which
without any acknowledge. These two methods have been supported in the
driver. For receiving data, it will depend on the interrupt to notify
the channel has incoming message.

Now mailbox driver is used to send message to MCU to control dynamic
voltage and frequency scaling for CPU, GPU and DDR.
Signed-off-by: Leo Yan <leo.yan@linaro.org>
Signed-off-by: Jassi Brar <jaswinder.singh@linaro.org>

Document DT binding for Hisilicon Hi6220 mailbox driver.
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Leo Yan <leo.yan@linaro.org>
Signed-off-by: Jassi Brar <jaswinder.singh@linaro.org>

This patch adds support for different MMIO region for Tx and Rx paths.
If only one region is specified, it's assumed to be shared between Rx
and Tx, thereby retaining backward compatibility.

Also in order to support single channel dealing with both Tx and Rx with
dedicated MMIO regions, Tx channel itself is assigned to Rx if MMIO
regions are different and Rx is not specified.
Acked-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
Signed-off-by: Jassi Brar <jaswinder.singh@linaro.org>

Reduce the logging from info to debug. Also use print_hex_dump_bytes
instead as it has support for dynamic printk providing options to
conditionally enable/disable these logs.

Cc: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
Signed-off-by: Jassi Brar <jaswinder.singh@linaro.org>

Underscores are usually forbidden in the compatible strings. So lets
remove it before the first users of this is seen.
Acked-by: Rob Herring <robh@kernel.org>
Acked-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
Signed-off-by: Jassi Brar <jaswinder.singh@linaro.org>

This mailbox-test driver was designed to be generic, so let's remove ST
tag on it and make it generic.
Acked-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
Signed-off-by: Jassi Brar <jaswinder.singh@linaro.org>

This adds the APM X-Gene SLIMpro mailbox device tree
node documentation.
Signed-off-by: Feng Kan <fkan@apm.com>
Signed-off-by: Duc Dang <dhdang@apm.com>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Jassi Brar <jaswinder.singh@linaro.org>

X-Gene mailbox controller provides 8 mailbox channels, with
each channel has a dedicated interrupt line.
Signed-off-by: Feng Kan <fkan@apm.com>
Signed-off-by: Duc Dang <dhdang@apm.com>
Signed-off-by: Jassi Brar <jaswinder.singh@linaro.org>

Update the mailing list used for development of support for ARM64
Renesas SoCs.

This is a follow-up for a similar change for other Renesas SoCs and
drivers uses by Renesas SoCs.  The ARM64 SoC entry was not updated in
that patch as it was not yet present in mainline.

The motivation for the mailing list update is that Renesas SoCs are now
much wider than the SH architecture and there is some desire from some
for the linux-sh list to refocus on discussion of the work on the SH
architecture.
Acked-by: Magnus Damm <damm@opensource.se>
Acked-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Pull i915 drm fixes from Dave Airlie:
 "Jani sent a bunch of i915 display fixes as my weekend started, but
  hopefully you can fit them in"

* 'drm-fixes' of git://people.freedesktop.org/~airlied/linux:
  drm/i915: fix error path in intel_setup_gmbus()
  drm/i915/skl: Fix typo in DPLL_CFGCR1 definition
  drm/i915/skl: Don't skip mst encoders in skl_ddi_pll_select()
  drm/i915: Pretend cursor is always on for ILK-style WM calculations (v2)
  drm/i915/dp: reduce missing TPS3 support errors to debug logging
  drm/i915/dp: abstract training pattern selection
  drm/i915/dsi: skip gpio element execution when not supported
  drm/i915/dsi: don't pass arbitrary data to sideband
  drm/i915/dsi: defend gpio table against out of bounds access
  drm/i915/bxt: Don't save/restore eDP panel power during suspend (v3)
  drm/i915: Allow i915_gem_object_get_page() on userptr as well

i915 display fixes mostly.

* tag 'drm-intel-fixes-2016-02-12' of git://anongit.freedesktop.org/drm-intel:
  drm/i915: fix error path in intel_setup_gmbus()
  drm/i915/skl: Fix typo in DPLL_CFGCR1 definition
  drm/i915/skl: Don't skip mst encoders in skl_ddi_pll_select()
  drm/i915: Pretend cursor is always on for ILK-style WM calculations (v2)
  drm/i915/dp: reduce missing TPS3 support errors to debug logging
  drm/i915/dp: abstract training pattern selection
  drm/i915/dsi: skip gpio element execution when not supported
  drm/i915/dsi: don't pass arbitrary data to sideband
  drm/i915/dsi: defend gpio table against out of bounds access
  drm/i915/bxt: Don't save/restore eDP panel power during suspend (v3)
  drm/i915: Allow i915_gem_object_get_page() on userptr as well

Pull char/misc driver fixes from Greg KH:
 "Here are 3 fixes for some reported issues.  Two nvmem driver fixes,
  and one mei fix.  All have been in linux-next just fine"

* tag 'char-misc-4.5-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc:
  nvmem: qfprom: Specify LE device endianness
  nvmem: core: return error for non word aligned access
  mei: validate request value in client notify request ioctl

Pull driver core fix from Greg KH:
 "Here is one driver core, well klist, fix for 4.5-rc4.

  It fixes a problem found in the scsi device list traversal that
  probably also could be triggered by other subsystems.

  The fix has been in linux-next for a while with no reported problems"

* tag 'driver-core-4.5-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core:
  klist: fix starting point removed bug in klist iterators

Pull tty/serial fixes from Greg KH:
 "Here are a number of small tty and serial driver fixes for 4.5-rc4
  that resolve some reported issues.

  One of them got reverted as it wasn't correct based on testing, and
  all have been in linux-next for a while"

* tag 'tty-4.5-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty:
  Revert "8250: uniphier: allow modular build with 8250 console"
  pty: make sure super_block is still valid in final /dev/tty close
  pty: fix possible use after free of tty->driver_data
  tty: Add support for PCIe WCH382 2S multi-IO card
  serial/omap: mark wait_for_xmitr as __maybe_unused
  serial: omap: Prevent DoS using unprivileged ioctl(TIOCSRS485)
  8250: uniphier: allow modular build with 8250 console
  tty: Drop krefs for interrupted tty lock

Pull PHY fixes from Greg KH:
 "Here are a couple of PHY driver fixes for 4.5-rc4.

  A few small phy issues.  All have been in linux-next with no reported
  issues"

* tag 'usb-4.5-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb:
  phy: twl4030-usb: Fix unbalanced pm_runtime_enable on module reload
  phy: twl4030-usb: Relase usb phy on unload
  phy: core: fix wrong err handle for phy_power_on
  phy: Restrict phy-hi6220-usb to HiSilicon arm64

Pull perf tooling fixes from Thomas Gleixner:
 "Another round of fixes for the perf tooling side:

   - Prevent a NULL pointer dereference in tracepoint error handling

   - Fix a thread handling bug in the intel_pt error handling code

   - Search both .eh_frame and .debug_frame sections as toolchains seem
     to have random choices of storing the CFI information

   - Fix the perf state interval output values, which got broken when
     fixing the overall output"

* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  perf stat: Fix interval output values
  perf probe: Search both .eh_frame and .debug_frame sections for probe location
  perf tools: Fix thread lifetime related segfaut in intel_pt
  perf tools: tracepoint_error() can receive e=NULL, robustify it

Pull lockdep fix from Thomas Gleixner:
 "A single fix for the stack trace caching logic in lockdep, where the
  duplicate avoidance managed to store no back trace at all"

* 'locking-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  locking/lockdep: Fix stack trace caching logic

Pull timer fix from Thomas Gleixner:
 "A single fix preventing a 32bit overflow in timespec/val to cputime
  conversions on 32bit machines"

* 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  cputime: Prevent 32bit overflow in time[val|spec]_to_cputime()

Pull irqchip fixes from Thomas Gleixner:
 "Another set of ARM SoC related irqchip fixes:
   - Plug a memory leak in gicv3-its
   - Limit features to the root gic interrupt controller
   - Add a missing barrier in the gic-v3 IAR access
   - Another compile test fix for sun4i"

* 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  irqchip/gic-v3: Make sure read from ICC_IAR1_EL1 is visible on redestributor
  irqchip/gic: Only set the EOImodeNS bit for the root controller
  irqchip/gic: Only populate set_affinity for the root controller
  irqchip/gicv3-its: Fix memory leak in its_free_tables()
  irqchip/sun4i: Fix compilation outside of arch/arm

Pull x86 fixes from Thomas Gleixner:
 "Two small fixlets for x86:

   - Prevent a KASAN false positive in thread_saved_pc()

   - Fix a 32-bit truncation problem in the x86 numa code"

* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/mm/numa: Fix 32-bit memblock range truncation bug on 32-bit NUMA kernels
  x86: Fix KASAN false positives in thread_saved_pc()

Pull MIPS fixes from Ralf Baechle:
 "Here's the first round of MIPS fixes after the merge window:

   - Detect Octeon III's PCI correctly.
   - Fix return value of the MT7620 probing function.
   - Wire up the copy_file_range syscall.
   - Fix 64k page support on 32 bit kernels.
   - Fix the early Coherency Manager probe.
   - Allow only hardware-supported page sizes to be selected for R6000.
   - Fix corner cases for the RDHWR nstruction emulation on old hardware.
   - Fix FPU handling corner cases.
   - Remove stale entry for BCM33xx from the MAINTAINERS file.
   - 32 and 64 bit ELF headers are different, handle them correctly"

* 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus:
  mips: Differentiate between 32 and 64 bit ELF header
  MIPS: Octeon: Update OCTEON_FEATURE_PCIE for Octeon III
  MIPS: pci-mt7620: Fix return value check in mt7620_pci_probe()
  MIPS: Fix early CM probing
  MIPS: Wire up copy_file_range syscall.
  MIPS: Fix 64k page support for 32 bit kernels.
  MIPS: R6000: Don't allow 64k pages for R6000.
  MIPS: traps.c: Correct microMIPS RDHWR emulation
  MIPS: traps.c: Don't emulate RDHWR in the CpU #0 exception handler
  MAINTAINERS: Remove stale entry for BCM33xx chips
  MIPS: Fix FPU disable with preemption
  MIPS: Properly disable FPU in start_thread()
  MIPS: Fix buffer overflow in syscall_get_arguments()

Pull ARM fixes from Russell King:
 "A couple of ARM fixes from Linus for the ICST clock generator code"

[ "Linus" here is Linus Walleij.  Name-stealer.

       Linus "there can be only one" Torvalds ]

* 'fixes' of git://ftp.arm.linux.org.uk/~rmk/linux-arm:
  ARM: 8519/1: ICST: try other dividends than 1
  ARM: 8517/1: ICST: avoid arithmetic overflow in icst_hz()

Pull component helper fixes from Russell King:
 "A few fixes for problems people have encountered with the recent
  update to the component helpers"

* 'component' of git://ftp.arm.linux.org.uk/~rmk/linux-arm:
  component: remove device from master match list on failed add
  component: Detach components when deleting master struct
  component: fix crash on x86_64 with hda audio drivers

Pull more rdma fixes from Doug Ledford:
 "I think we are getting pretty close to done now.  There are four
  one-off fixes in this update:

   - fix ipoib multicast joins
   - fix mlx4 error handling
   - fix mlx5 size computation
   - fix a thinko in core code"

* tag 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dledford/rdma:
  IB/mlx5: Fix RC transport send queue overhead computation
  IB/ipoib: fix for rare multicast join race condition
  IB/core: Fix reading capability mask of the port info class
  net/mlx4: fix some error handling in mlx4_multi_func_init()

Pull SCSI target fixes from Nicholas Bellinger:
 "This includes the long awaited series to address a set of bugs around
  active I/O remote-port LUN_RESET, as well as properly handling this
  same case with concurrent fabric driver session disconnect ->
  reconnect.

  Note this set of LUN_RESET bug-fixes has been surviving extended
  testing on both v4.5-rc1 and v3.14.y code over the last weeks, and is
  CC'ed for stable as it's something folks using multiple ESX connected
  hosts with slow backends can certainly trigger.

  The highlights also include:

   - Fix WRITE_SAME/DISCARD emulation 4k sector conversion in
     target/iblock (Mike Christie)

   - Fix TMR abort interaction and AIO type TMR response in qla2xxx
     target (Quinn Tran + Swapnil Nagle)

   - Fix >= v3.17 stale descriptor pointer regression in qla2xxx target
     (Quinn Tran)

   - Fix >= v4.5-rc1 return regression with unmap_zeros_data_store new
     configfs store handler (nab)

   - Add CPU affinity flag + convert qla2xxx to use bit (Quinn + HCH +
     Bart)"

* git://git.kernel.org/pub/scm/linux/kernel/git/nab/target-pending:
  qla2xxx: use TARGET_SCF_USE_CPUID flag to indiate CPU Affinity
  target/transport: add flag to indicate CPU Affinity is observed
  target: Fix incorrect unmap_zeroes_data_store return
  qla2xxx: Use ATIO type to send correct tmr response
  qla2xxx: Fix stale pointer access.
  target/user: Fix cast from pointer to phys_addr_t
  target: Drop legacy se_cmd->task_stop_comp + REQUEST_STOP usage
  target: Fix race with SCF_SEND_DELAYED_TAS handling
  target: Fix remote-port TMR ABORT + se_cmd fabric stop
  target: Fix TAS handling for multi-session se_node_acls
  target: Fix LUN_RESET active TMR descriptor handling
  target: Fix LUN_RESET active I/O handling for ACK_KREF
  qla2xxx: Fix TMR ABORT interaction issue between qla2xxx and TCM
  qla2xxx: Fix warning reported by static checker
  target: Fix WRITE_SAME/DISCARD conversion to linux 512b sectors

Pull thermal management fixes from Eduardo Valentin:
 "Specifics in this pull request:

   - Compilation fixes on SPEAR, and U8500 thermal drivers.
   - RCAR thermal driver now recognizes OF-thermal based thermal zones.
   - Small code rework on OF-thermal.
   - These change have been CI tested using KernelCI bot [1,2].  \o/

  I am taking over on Rui's behalf while he is out.  Happy New Chinese
  Year!

  [1] - https://kernelci.org/build/evalenti/kernel/v4.5-rc3-16-ga53b8394ec3c/
  [2] - https://kernelci.org/boot/all/job/evalenti/kernel/v4.5-rc3-16-ga53b8394ec3c/"

* 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/evalenti/linux-soc-thermal:
  thermal: cpu_cooling: fix out of bounds access in time_in_idle
  thermal: allow u8500-thermal driver to be a module
  thermal: allow spear-thermal driver to be a module
  thermal: spear: use __maybe_unused for PM functions
  thermal: rcar: enable to use thermal-zone on DT
  thermal: of: use for_each_available_child_of_node for child iterator

Pull another sound fix from Takashi Iwai:
 "This contains a fix for the double-free of usb-audio MIDI device at
  probe failure"

* tag 'sound-fix-4.5-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound:
  ALSA: usb-audio: avoid freeing umidi object twice

Pull ARC fixes from Vineet Gupta:
 "I've been sitting on some of these fixes for a while.

   - Corner case of returning to delay slot from interrupt
   - Changing default interrupt prioiry level
   - Kconfig'ize support for super pages
   - Other minor fixes"

* tag 'arc-4.5-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/vgupta/arc:
  ARC: mm: Introduce explicit super page size support
  ARCv2: intc: Allow interruption by lowest priority interrupt
  ARCv2: Check for LL-SC livelock only if LLSC is enabled
  ARC: shrink cpuinfo by not saving full timer BCR
  ARCv2: clocksource: Rename GRTC -> GFRC ...
  ARCv2: STAR 9000950267: Handle return from intr to Delay Slot #2

The 'umidi' object will be free'd on the error path by snd_usbmidi_free()
when tearing down the rawmidi interface. So we shouldn't try to free it
in snd_usbmidi_create() after having registered the rawmidi interface.

Found by KASAN.
Signed-off-by: Andrey Konovalov <andreyknvl@gmail.com>
Acked-by: Clemens Ladisch <clemens@ladisch.de>
Cc: <stable@vger.kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

Pull PCI fixes from Bjorn Helgaas:
 "These are some Renesas binding updates for PCI host controllers, a
  Broadcom fix for a regression we added in v4.5-rc1, and a fix for an
  AER use-after-free problem that can cause memory corruption.

  Summary:

  AER:
    Flush workqueue on device remove to avoid use-after-free (Sebastian Andrzej Siewior)

  Broadcom iProc host bridge driver:
    Allow multiple devices except on PAXC (Ray Jui)

  Renesas R-Car host bridge driver:
    Add gen2 device tree support for r8a7793 (Simon Horman)
    Add device tree support for r8a7793 (Simon Horman)"

* tag 'pci-v4.5-fixes-1' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci:
  PCI: rcar: Add device tree support for r8a7793
  PCI: rcar: Add gen2 device tree support for r8a7793
  PCI: iproc: Allow multiple devices except on PAXC
  PCI/AER: Flush workqueue on device remove to avoid use-after-free

Merge fixes from Andrew Morton:
 "10 fixes"

The lockdep hlist conversion is in the locking tree too, waiting for the
next merge window.  Andrew thought it should go in now.  I'll take it,
since it fixes a real problem and looks trivially correct (famous last
words).

* emailed patches from Andrew Morton <akpm@linux-foundation.org>:
  arch/x86/Kconfig: CONFIG_X86_UV should depend on CONFIG_EFI
  mm: fix pfn_t vs highmem
  kernel/locking/lockdep.c: convert hash tables to hlists
  mm,thp: fix spellos in describing __HAVE_ARCH_FLUSH_PMD_TLB_RANGE
  mm,thp: khugepaged: call pte flush at the time of collapse
  mm/backing-dev.c: fix error path in wb_init()
  mm, dax: check for pmd_none() after split_huge_pmd()
  vsprintf: kptr_restrict is okay in IRQ when 2
  mm: fix filemap.c kernel doc warning
  ubsan: cosmetic fix to Kconfig text

Fix the RC QPs send queue overhead computation to take into account
two additional segments in the WQE which are needed for registration
operations.

The ATOMIC and UMR segments can't coexist together, so chose maximum out
of them.

The commit 9e65dc37 ("IB/mlx5: Fix RC transport send queue overhead
computation") was intended to update RC transport as commit messages
states, but added the code to UC transport.

Fixes: 9e65dc37 ("IB/mlx5: Fix RC transport send queue overhead computation")
Signed-off-by: Kamal Heib <kamalh@mellanox.com>
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Reviewed-by: Sagi Grimberg <sagig@mellanox.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>

A narrow window for race condition still exist between
multicast join thread and *dev_flush workers.
A kernel crash caused by prolong erratic link state changes
was observed (most likely a faulty cabling):

[167275.656270] BUG: unable to handle kernel NULL pointer dereference at
0000000000000020
[167275.665973] IP: [<ffffffffa05f8f2e>] ipoib_mcast_join+0xae/0x1d0 [ib_ipoib]
[167275.674443] PGD 0
[167275.677373] Oops: 0000 [#1] SMP
...
[167275.977530] Call Trace:
[167275.982225]  [<ffffffffa05f92f0>] ? ipoib_mcast_free+0x200/0x200 [ib_ipoib]
[167275.992024]  [<ffffffffa05fa1b7>] ipoib_mcast_join_task+0x2a7/0x490
[ib_ipoib]
[167276.002149]  [<ffffffff8109d5fb>] process_one_work+0x17b/0x470
[167276.010754]  [<ffffffff8109e3cb>] worker_thread+0x11b/0x400
[167276.019088]  [<ffffffff8109e2b0>] ? rescuer_thread+0x400/0x400
[167276.027737]  [<ffffffff810a5aef>] kthread+0xcf/0xe0
Here was a hit spot:
ipoib_mcast_join() {
..............
      rec.qkey      = priv->broadcast->mcmember.qkey;
                                       ^^^^^^^
.....
 }
Proposed patch should prevent multicast join task to continue
if link state change is detected.
Signed-off-by: Alex Estrin <alex.estrin@intel.com>

Changes from v4:
- as suggested by Doug Ledford, optimized spinlock usage,
i.e. ipoib_mcast_join() is called with lock held.
Changes from v3:
- sync with priv->lock before flag check.
Chages from v2:
- Move check for OPER_UP flag state to mcast_join() to
ensure no event worker is in progress.
- minor style fixes.
Changes from v1:
- No need to lock again if error detected.
Signed-off-by: Doug Ledford <dledford@redhat.com>