If the input can be created earlier during probe, we can already populate
them while reading the report descriptor. This way, we can rely on the
hid subsystem directly for tablets which already provide a meaningful
report descriptor (like ISDv4-5).

This patch only splits the allocation and registration, but do not
change where we allocate the input. This will come in a later patch.
Signed-off-by: NBenjamin Tissoires <benjamin.tissoires@redhat.com>
Acked-by: NJason Gerecke <killertofu@gmail.com>
Signed-off-by: NJiri Kosina <jkosina@suse.cz>

When we have to deal with new elements in probe, having the exit labels
named sequencially is a pain to maintain. Put a meaningful name instead
so that we do not have to renumber them on inserts.
Signed-off-by: NBenjamin Tissoires <benjamin.tissoires@redhat.com>
Acked-by: NJason Gerecke <killertofu@gmail.com>
Signed-off-by: NJiri Kosina <jkosina@suse.cz>

Some Wacom tablets (at least the ISDv4 found in the Lenovo X230) timeout
during probe while retrieving the input reports.
The only time this information is valuable is during the feature_mapping
stage, so we can ask for it there and discard the generic input reports
retrieval.

This gives a code path closer to the wacom.ko driver when it was in the
input subtree (not HID).

Cc: stable@vger.kernel.org # requires cherry-pick of c64d8834Signed-off-by: NBenjamin Tissoires <benjamin.tissoires@redhat.com>
Signed-off-by: NJiri Kosina <jkosina@suse.cz>

Currently, tablets connected to the WL receiver all share the same
VID/PID. There is no way for the user space to know which one is which
besides parsing the name. We can force the PID to be set to the
actual hardware. This way, the input device will have the correct PID
which can be match in libwacom.

With only this trick, the pad input does not inherit the ID_INPUT_TABLET
udev property from its parent. We can force udev to accept it by declaring
a BTN_STYLUS which is never used.

This way, tablets connected through WL can be used from the user point of
view in the same way they are used while connected through wire.
Signed-off-by: NBenjamin Tissoires <benjamin.tissoires@redhat.com>
Reviewed-by: NPing Cheng <pingc@wacom.com>
Signed-off-by: NJiri Kosina <jkosina@suse.cz>

And associate all LED/OLED to PAD device
Signed-off-by: NPing Cheng <pingc@wacom.com>
Tested-by: NBenjamin Tissoires <benjamin.tissoires@redhat.com>
Signed-off-by: NJiri Kosina <jkosina@suse.cz>

It is assigned in buf[0] anyway.
Signed-off-by: NPing Cheng <pingc@wacom.com>
Reviewed-by: NBenjamin Tissoires <benjamin.tissoires@redhat.com>
Signed-off-by: NJiri Kosina <jkosina@suse.cz>

changed to scnprintf(buf, PAGE_SIZE, ... ) as suggested in sysfs.txt
for show functions
Signed-off-by: NPaul A. Tessier <phernost@gmail.com>
Signed-Off-by: NPing Cheng <pingc@wacom.com>
Tested-by: NBenjamin Tissoires <benjamin.tissoires@redhat.com>
Signed-off-by: NJiri Kosina <jkosina@suse.cz>

RW : ug=rw,o=r
WO : ug=w

And enabled reading relavent sysfs attributes.
Signed-off-by: NPaul A. Tessier <phernost@gmail.com>
Signed-Off-by: NPing Cheng <pingc@wacom.com>
Tested-by: NBenjamin Tissoires <benjamin.tissoires@redhat.com>
Signed-off-by: NJiri Kosina <jkosina@suse.cz>

The Wacom Cintiq Companion shares the same sensor than the Cintiq
Companion Hybrid, with the exception of the different PIDs.
Signed-off-by: NBenjamin Tissoires <benjamin.tissoires@redhat.com>
Signed-off-by: NJiri Kosina <jkosina@suse.cz>

Pull HID fixes from Jiri Kosina:

 - fixes for potential memory corruption problems in magicmouse and
   picolcd drivers (the HW would have to be manufactured to be
   deliberately evil to trigger those) which were found by Steven
   Vittitoe

 - fix for false error message appearing in dmesg from logitech-dj
   driver, from Benjamin Tissoires

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/hid:
  HID: picolcd: sanity check report size in raw_event() callback
  HID: magicmouse: sanity check report size in raw_event() callback
  HID: logitech-dj: prevent false errors to be shown

Pull btrfs fixes from Chris Mason:
 "The biggest of these comes from Liu Bo, who tracked down a hang we've
  been hitting since moving to kernel workqueues (it's a btrfs bug, not
  in the generic code).  His patch needs backporting to 3.16 and 3.15
  stable, which I'll send once this is in.

  Otherwise these are assorted fixes.  Most were integrated last week
  during KS, but I wanted to give everyone the chance to test the
  result, so I waited for rc2 to come out before sending"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs: (24 commits)
  Btrfs: fix task hang under heavy compressed write
  Btrfs: fix filemap_flush call in btrfs_file_release
  Btrfs: fix crash on endio of reading corrupted block
  btrfs: fix leak in qgroup_subtree_accounting() error path
  btrfs: Use right extent length when inserting overlap extent map.
  Btrfs: clone, don't create invalid hole extent map
  Btrfs: don't monopolize a core when evicting inode
  Btrfs: fix hole detection during file fsync
  Btrfs: ensure tmpfile inode is always persisted with link count of 0
  Btrfs: race free update of commit root for ro snapshots
  Btrfs: fix regression of btrfs device replace
  Btrfs: don't consider the missing device when allocating new chunks
  Btrfs: Fix wrong device size when we are resizing the device
  Btrfs: don't write any data into a readonly device when scrub
  Btrfs: Fix the problem that the replace destroys the seed filesystem
  btrfs: Return right extent when fiemap gives unaligned offset and len.
  Btrfs: fix wrong extent mapping for DirectIO
  Btrfs: fix wrong write range for filemap_fdatawrite_range()
  Btrfs: fix wrong missing device counter decrease
  Btrfs: fix unzeroed members in fs_devices when creating a fs from seed fs
  ...

Merge tag 'trace-fixes-v3.17-rc1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

Pull trace buffer epoll hang fix from Steven Rostedt:
 "Josef Bacik found a bug in the ring_buffer_poll_wait() where the
  condition variable (waiters_pending) was set before being added to the
  poll queue via poll_wait().  This allowed for a small race window to
  happen where an event could come in, check the condition variable see
  it set to true, clear it, and then wake all the waiters.  But because
  the waiter set the variable before adding itself to the queue, the
  waker could have cleared the variable after it was set and then miss
  waking it up as it wasn't added to the queue yet.

  Discussing this bug, we realized that a memory barrier needed to be
  added too, for the rare case that something polls for a single trace
  event to happen (and just one, no more to come in), and miss the
  wakeup due to memory ordering.  Ideally, a memory barrier needs to be
  added on the writer side too, but as that will kill tracing
  performance and this is for a situation that tracing wasn't even
  designed for (who traces one instance of an event, use a printk
  instead!), this isn't worth adding the barrier.  But we can in the
  future add the barrier for when the buffer goes from empty to the
  first event, as that would cover this case"

* tag 'trace-fixes-v3.17-rc1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  trace: Fix epoll hang when we race with new entries

The report passed to us from transport driver could potentially be
arbitrarily large, therefore we better sanity-check it so that raw_data
that we hold in picolcd_pending structure are always kept within proper
bounds.

Cc: stable@vger.kernel.org
Reported-by: NSteven Vittitoe <scvitti@google.com>
Signed-off-by: NJiri Kosina <jkosina@suse.cz>

The report passed to us from transport driver could potentially be
arbitrarily large, therefore we better sanity-check it so that
magicmouse_emit_touch() gets only valid values of raw_id.

Cc: stable@vger.kernel.org
Reported-by: NSteven Vittitoe <scvitti@google.com>
Signed-off-by: NJiri Kosina <jkosina@suse.cz>

Pull s390 updates from Martin Schwidefsky:
 - wire up the system calls seccomp, getrandom and memfd_create
 - use static system information as input to add_device_randomness
 - .. and three bug fixes

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux:
  s390/sclp: remove unnecessary XTABS flag
  s390/3215: fix tty output containing tabs
  s390: wire up memfd_create syscall
  s390: add system information as device randomness
  s390/kdump: Clear subchannel ID to signal non-CCW/SCSI IPL
  s390: wire up seccomp and getrandom syscalls

Update the description for per cpu operations to clarify use cases of
this_cpu operations and add considerations for remote access.
Signed-off-by: NPranith Kumar <bobby.prani@gmail.com>
Signed-off-by: NChristoph Lameter <cl@linux.com>
Signed-off-by: NRandy Dunlap <rdunlap@infradead.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Fix scripts/kernel-doc to recognize __meminit in a function prototype
and to strip it, as done with many other attributes.

Fixes this warning:

  Warning(..//mm/page_alloc.c:2973): cannot understand function prototype: 'void * __meminit alloc_pages_exact_nid(int nid, size_t size, gfp_t gfp_mask) '
Signed-off-by: NRandy Dunlap <rdunlap@infradead.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Epoll on trace_pipe can sometimes hang in a weird case.  If the ring buffer is
empty when we set waiters_pending but an event shows up exactly at that moment
we can miss being woken up by the ring buffers irq work.  Since
ring_buffer_empty() is inherently racey we will sometimes think that the buffer
is not empty.  So we don't get woken up and we don't think there are any events
even though there were some ready when we added the watch, which makes us hang.
This patch fixes this by making sure that we are actually on the wait list
before we set waiters_pending, and add a memory barrier to make sure
ring_buffer_empty() is going to be correct.

Link: http://lkml.kernel.org/p/1408989581-23727-1-git-send-email-jbacik@fb.com

Cc: stable@vger.kernel.org # 3.10+
Cc: Martin Lau <kafai@fb.com>
Signed-off-by: NJosef Bacik <jbacik@fb.com>
Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>

Pull NFS client fixes from Trond Myklebust:
 "Highlights:

   - more fixes for read/write codepath regressions
     * sleeping while holding the inode lock
     * stricter enforcement of page contiguity when coalescing requests
     * fix up error handling in the page coalescing code

   - don't busy wait on SIGKILL in the file locking code"

* tag 'nfs-for-3.17-2' of git://git.linux-nfs.org/projects/trondmy/linux-nfs:
  nfs: Don't busy-wait on SIGKILL in __nfs_iocounter_wait
  nfs: can_coalesce_requests must enforce contiguity
  nfs: disallow duplicate pages in pgio page vectors
  nfs: don't sleep with inode lock in lock_and_join_requests
  nfs: fix error handling in lock_and_join_requests
  nfs: use blocking page_group_lock in add_request
  nfs: fix nonblocking calls to nfs_page_group_lock
  nfs: change nfs_page_group_lock argument

Merge tag 'renesas-sh-drivers-for-v3.17' of git://git.kernel.org/pub/scm/linux/kernel/git/horms/renesas

Pull SH driver fix from Simon Horman:
 "Confine SH_INTC to platforms that need it"

* tag 'renesas-sh-drivers-for-v3.17' of git://git.kernel.org/pub/scm/linux/kernel/git/horms/renesas:
  sh: intc: Confine SH_INTC to platforms that need it

Pull MIPS fixes from Ralf Baechle:
 "Pretty much all across the field so with this we should be in
  reasonable shape for the upcoming -rc2"

* 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus:
  MIPS: OCTEON: make get_system_type() thread-safe
  MIPS: CPS: Initialize EVA before bringing up VPEs from secondary cores
  MIPS: Malta: EVA: Rename 'eva_entry' to 'platform_eva_init'
  MIPS: EVA: Add new EVA header
  MIPS: scall64-o32: Fix indirect syscall detection
  MIPS: syscall: Fix AUDIT value for O32 processes on MIPS64
  MIPS: Loongson: Fix COP2 usage for preemptible kernel
  MIPS: NL: Fix nlm_xlp_defconfig build error
  MIPS: Remove race window in page fault handling
  MIPS: Malta: Improve system memory detection for '{e, }memsize' >= 2G
  MIPS: Alchemy: Fix db1200 PSC clock enablement
  MIPS: BCM47XX: Fix reboot problem on BCM4705/BCM4785
  MIPS: Remove duplicated include from numa.c
  MIPS: Add common plat_irq_dispatch declaration
  MIPS: MSP71xx: remove unused plat_irq_dispatch() argument
  MIPS: GIC: Remove useless parens from GICBIS().
  MIPS: perf: Mark pmu interupt IRQF_NO_THREAD

Merge tag 'trace-fixes-v3.17-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

Pull fix for ftrace function tracer/profiler conflict from Steven Rostedt:
 "The rewrite of the ftrace code that makes it possible to allow for
  separate trampolines had a design flaw with the interaction between
  the function and function_graph tracers.

  The main flaw was the simplification of the use of multiple tracers
  having the same filter (like function and function_graph, that use the
  set_ftrace_filter file to filter their code).  The design assumed that
  the two tracers could never run simultaneously as only one tracer can
  be used at a time.  The problem with this assumption was that the
  function profiler could be implemented on top of the function graph
  tracer, and the function profiler could run at the same time as the
  function tracer.  This caused the assumption to be broken and when
  ftrace detected this failed assumpiton it would spit out a nasty
  warning and shut itself down.

  Instead of using a single ftrace_ops that switches between the
  function and function_graph callbacks, the two tracers can again use
  their own ftrace_ops.  But instead of having a complex hierarchy of
  ftrace_ops, the filter fields are placed in its own structure and the
  ftrace_ops can carefully use the same filter.  This change took a bit
  to be able to allow for this and currently only the global_ops can
  share the same filter, but this new design can easily be modified to
  allow for any ftrace_ops to share its filter with another ftrace_ops.

  The first four patches deal with the change of allowing the ftrace_ops
  to share the filter (and this needs to go to 3.16 as well).

  The fifth patch fixes a bug that was also caused by the new changes
  but only for archs other than x86, and only if those archs implement a
  direct call to the function_graph tracer which they do not do yet but
  will in the future.  It does not need to go to stable, but needs to be
  fixed before the other archs update their code to allow direct calls
  to the function_graph trampoline"

* tag 'trace-fixes-v3.17-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  ftrace: Use current addr when converting to nop in __ftrace_replace_code()
  ftrace: Fix function_profiler and function tracer together
  ftrace: Fix up trampoline accounting with looping on hash ops
  ftrace: Update all ftrace_ops for a ftrace_hash_ops update
  ftrace: Allow ftrace_ops to use the hashes from other ops

Commit "HID: logitech: perform bounds checking on device_id early
enough" unfortunately leaks some errors to dmesg which are not real
ones:
- if the report is not a DJ one, then there is not point in checking
  the device_id
- the receiver (index 0) can also receive some notifications which
  can be safely ignored given the current implementation

Move out the test regarding the report_id and also discards
printing errors when the receiver got notified.

Fixes: ad3e14d7

Cc: stable@vger.kernel.org
Reported-and-tested-by: NMarkus Trippelsdorf <markus@trippelsdorf.de>
Signed-off-by: NBenjamin Tissoires <benjamin.tissoires@redhat.com>
Signed-off-by: NJiri Kosina <jkosina@suse.cz>

Pull x86 fixes from Ingo Molnar:
 "A couple of EFI fixes, plus misc fixes all around the map"

* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  efi/arm64: Store Runtime Services revision
  firmware: Do not use WARN_ON(!spin_is_locked())
  x86_32, entry: Clean up sysenter_badsys declaration
  x86/doc: Fix the 'tlb_single_page_flush_ceiling' sysconfig path
  x86/mm: Fix sparse 'tlb_single_page_flush_ceiling' warning and make the variable read-mostly
  x86/mm: Fix RCU splat from new TLB tracepoints

Pull perf fixes from Ingo Molnar:
 "A kprobes and a perf compat ioctl fix"

* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  perf: Handle compat ioctl
  kprobes: Skip kretprobe hit in NMI context to avoid deadlock

Pull ARM SoC fixes from Olof Johansson:
 "A collection of fixes from this week, it's been pretty quiet and
  nothing really stands out as particularly noteworthy here -- mostly
  minor fixes across the field:

   - ODROID booting was fixed due to PMIC interrupts missing in DT
   - a collection of i.MX fixes
   - minor Tegra fix for regulators
   - Rockchip fix and addition of SoC-specific mailing list to make it
     easier to find posted patches"

* tag 'fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc:
  bus: arm-ccn: Fix warning message
  ARM: shmobile: koelsch: Remove non-existent i2c6 pinmux
  ARM: tegra: apalis/colibri t30: fix on-module 5v0 supplies
  MAINTAINERS: add new Rockchip SoC list
  ARM: dts: rockchip: readd missing mmc0 pinctrl settings
  ARM: dts: ODROID i2c improvements
  ARM: dts: Enable PMIC interrupts on ODROID
  ARM: dts: imx6sx: fix the pad setting for uart CTS_B
  ARM: dts: i.MX53: fix apparent bug in VPU clks
  ARM: imx: correct gpu2d_axi and gpu3d_axi clock setting
  ARM: dts: imx6: edmqmx6: change enet reset pin
  ARM: dts: vf610-twr: Fix pinctrl_esdhc1 pin definitions.
  ARM: imx: remove unnecessary ARCH_HAS_OPP select
  ARM: imx: fix TLB missing of IOMUXC base address during suspend
  ARM: imx6: fix SMP compilation again
  ARM: dt: sun6i: Add #address-cells and #size-cells to i2c controller nodes

Pull gpio fixes from Linus Walleij:

 - a largeish fix for the IRQ handling in the new Zynq driver.  The
   quite verbose commit message gives the exact details.
 - move some defines for gpiod flags outside an ifdef to make stub
   functions work again.
 - various minor fixes that we can accept for -rc1.

* tag 'gpio-v3.17-2' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-gpio:
  gpio-lynxpoint: enable input sensing in resume
  gpio: move GPIOD flags outside #ifdef
  gpio: delete unneeded test before of_node_put
  gpio: zynq: Fix IRQ handlers
  gpiolib: devres: use correct structure type name in sizeof
  MAINTAINERS: Change maintainer for gpio-bcm-kona.c

Pull drm fixes from Dave Airlie:
 "Intel and radeon fixes.

  Post KS/LC git requests from i915 and radeon stacked up.  They are all
  fixes along with some new pci ids for radeon, and one maintainers file
  entry.

   - i915: display fixes and irq fixes
   - radeon: pci ids, and misc gpuvm, dpm and hdp cache"

* 'drm-fixes' of git://people.freedesktop.org/~airlied/linux: (29 commits)
  MAINTAINERS: Add entry for Renesas DRM drivers
  drm/radeon: add additional SI pci ids
  drm/radeon: add new bonaire pci ids
  drm/radeon: add new KV pci id
  Revert "drm/radeon: Use write-combined CPU mappings of ring buffers with PCIe"
  drm/radeon: fix active_cu mask on SI and CIK after re-init (v3)
  drm/radeon: fix active cu count for SI and CIK
  drm/radeon: re-enable selective GPUVM flushing
  drm/radeon: Sync ME and PFP after CP semaphore waits v4
  drm/radeon: fix display handling in radeon_gpu_reset
  drm/radeon: fix pm handling in radeon_gpu_reset
  drm/radeon: Only flush HDP cache for indirect buffers from userspace
  drm/radeon: properly document reloc priority mask
  drm/i915: don't try to retrain a DP link on an inactive CRTC
  drm/i915: make sure VDD is turned off during system suspend
  drm/i915: cancel hotplug and dig_port work during suspend and unload
  drm/i915: fix HPD IRQ reenable work cancelation
  drm/i915: take display port power domain in DP HPD handler
  drm/i915: Don't try to enable cursor from setplane when crtc is disabled
  drm/i915: Skip load detect when intel_crtc->new_enable==true
  ...

As reported by Dan Aloni, commit f8567a38 ("aio: fix aio request
leak when events are reaped by userspace") introduces a regression when
user code attempts to perform io_submit() with more events than are
available in the ring buffer.  Reverting that commit would reintroduce a
regression when user space event reaping is used.

Fixing this bug is a bit more involved than the previous attempts to fix
this regression.  Since we do not have a single point at which we can
count events as being reaped by user space and io_getevents(), we have
to track event completion by looking at the number of events left in the
event ring.  So long as there are as many events in the ring buffer as
there have been completion events generate, we cannot call
put_reqs_available().  The code to check for this is now placed in
refill_reqs_available().

A test program from Dan and modified by me for verifying this bug is available
at http://www.kvack.org/~bcrl/20140824-aio_bug.c .
Reported-by: NDan Aloni <dan@kernelim.com>
Signed-off-by: NBenjamin LaHaise <bcrl@kvack.org>
Acked-by: NDan Aloni <dan@kernelim.com>
Cc: Kent Overstreet <kmo@daterainc.com>
Cc: Mateusz Guzik <mguzik@redhat.com>
Cc: Petr Matousek <pmatouse@redhat.com>
Cc: stable@vger.kernel.org      # v3.16 and anything that f8567a38 was backported to
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

A message warning a user about wrong vc value was printing
out port instead.
Reported-by: NDrew Richardson <drew.richardson@arm.com>
Signed-off-by: NPawel Moll <pawel.moll@arm.com>
Signed-off-by: NOlof Johansson <olof@lixom.net>

On r8a7791, i2c6 (aka iic3) doesn't need pinmux, but the koelsch dts
refers to non-existent pinmux configuration data:

pinmux core: sh-pfc does not support function i2c6
sh-pfc e6060000.pfc: invalid function i2c6 in map table

Remove it to fix this.

Fixes: commit 1d41f36a ("ARM: shmobile:
       koelsch dts: Add VDD MPU regulator for DVFS")
Signed-off-by: NGeert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: NSimon Horman <horms+renesas@verge.net.au>
Signed-off-by: NOlof Johansson <olof@lixom.net>

Working on Gigabit/PCIe support in U-Boot for Apalis T30 I realised
that the current device tree source includes for our modules only
happen to work due to referencing the on-carrier 5v0 supply from USB
which is not at all available on-module. The modules actually contain
TPS60150 charge pumps to generate the PMIC required 5 volts from the
one and only 3.3 volt module supply. This patch fixes this.

(Note: When back-porting this to v3.16 stable releases, simply drop the
change to tegra30-apalis.dtsi; that file was added in v3.17)

Cc: <stable@vger.kernel.org> #v3.16+
Signed-off-by: NMarcel Ziswiler <marcel@ziswiler.com>
Signed-off-by: NStephen Warren <swarren@nvidia.com>
Signed-off-by: NOlof Johansson <olof@lixom.net>

Merge tag 'v3.17-rockchip-fixes1' of git://git.kernel.org/pub/scm/linux/kernel/git/mmind/linux-rockchip into fixes

Merge "ARM: rockchip: fix for 3.17" from Heiko Stubner:

Pinctrl that got accidentially dropped when reorganizing the
dts files and addition of the new Rockchip list to MAINTAINERS.

* tag 'v3.17-rockchip-fixes1' of git://git.kernel.org/pub/scm/linux/kernel/git/mmind/linux-rockchip:
  MAINTAINERS: add new Rockchip SoC list
  ARM: dts: rockchip: readd missing mmc0 pinctrl settings
Signed-off-by: NOlof Johansson <olof@lixom.net>

This has been reported and discussed for a long time, and this hang occurs in
both 3.15 and 3.16.

Btrfs now migrates to use kernel workqueue, but it introduces this hang problem.

Btrfs has a kind of work queued as an ordered way, which means that its
ordered_func() must be processed in the way of FIFO, so it usually looks like --

normal_work_helper(arg)
    work = container_of(arg, struct btrfs_work, normal_work);

    work->func() <---- (we name it work X)
    for ordered_work in wq->ordered_list
            ordered_work->ordered_func()
            ordered_work->ordered_free()

The hang is a rare case, first when we find free space, we get an uncached block
group, then we go to read its free space cache inode for free space information,
so it will

file a readahead request
    btrfs_readpages()
         for page that is not in page cache
                __do_readpage()
                     submit_extent_page()
                           btrfs_submit_bio_hook()
                                 btrfs_bio_wq_end_io()
                                 submit_bio()
                                 end_workqueue_bio() <--(ret by the 1st endio)
                                      queue a work(named work Y) for the 2nd
                                      also the real endio()

So the hang occurs when work Y's work_struct and work X's work_struct happens
to share the same address.

A bit more explanation,

A,B,C -- struct btrfs_work
arg   -- struct work_struct

kthread:
worker_thread()
    pick up a work_struct from @worklist
    process_one_work(arg)
	worker->current_work = arg;  <-- arg is A->normal_work
	worker->current_func(arg)
		normal_work_helper(arg)
		     A = container_of(arg, struct btrfs_work, normal_work);

		     A->func()
		     A->ordered_func()
		     A->ordered_free()  <-- A gets freed

		     B->ordered_func()
			  submit_compressed_extents()
			      find_free_extent()
				  load_free_space_inode()
				      ...   <-- (the above readhead stack)
				      end_workqueue_bio()
					   btrfs_queue_work(work C)
		     B->ordered_free()

As if work A has a high priority in wq->ordered_list and there are more ordered
works queued after it, such as B->ordered_func(), its memory could have been
freed before normal_work_helper() returns, which means that kernel workqueue
code worker_thread() still has worker->current_work pointer to be work
A->normal_work's, ie. arg's address.

Meanwhile, work C is allocated after work A is freed, work C->normal_work
and work A->normal_work are likely to share the same address(I confirmed this
with ftrace output, so I'm not just guessing, it's rare though).

When another kthread picks up work C->normal_work to process, and finds our
kthread is processing it(see find_worker_executing_work()), it'll think
work C as a collision and skip then, which ends up nobody processing work C.

So the situation is that our kthread is waiting forever on work C.

Besides, there're other cases that can lead to deadlock, but the real problem
is that all btrfs workqueue shares one work->func, -- normal_work_helper,
so this makes each workqueue to have its own helper function, but only a
wraper pf normal_work_helper.

With this patch, I no long hit the above hang.
Signed-off-by: NLiu Bo <bo.li.liu@oracle.com>
Signed-off-by: NChris Mason <clm@fb.com>

Signed-off-by: NLaurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Signed-off-by: NDave Airlie <airlied@gmail.com>

This pull just contains some new pci ids.

* 'drm-fixes-3.17' of git://people.freedesktop.org/~agd5f/linux:
  drm/radeon: add additional SI pci ids
  drm/radeon: add new bonaire pci ids
  drm/radeon: add new KV pci id

Add the new list that Rockchip-specific patches should also be directed to.
Signed-off-by: NHeiko Stuebner <heiko@sntech.de>

During the restructuring of the Rockchip Cortex-A9 dtsi files it seems
like the pinctrl settings vanished at some point from the mmc0 support.

This of course renders them unusable, so readd the necessary pinctrl
properties.
Signed-off-by: NHeiko Stuebner <heiko@sntech.de>

Merge tag 'sunxi-dt-for-3.17-2' of git://git.kernel.org/pub/scm/linux/kernel/git/mripard/linux into fixes

Merge "Allwinner DT changes, take 2" from Maxime Ripard:

Only a single patch in here that fixes a DTC warning.

* tag 'sunxi-dt-for-3.17-2' of git://git.kernel.org/pub/scm/linux/kernel/git/mripard/linux:
  ARM: dt: sun6i: Add #address-cells and #size-cells to i2c controller nodes
Signed-off-by: NOlof Johansson <olof@lixom.net>