The first offline/online cycle is successful, the second not.
Doing:
echo 0 >cpu1/online
echo 1 >cpu1/online
echo 0 >cpu1/online

The last command will trigger:
Jul 22 14:39:50 linux kernel: [  593.210125] ------------[ cut here ]------------
Jul 22 14:39:50 linux kernel: [  593.210139] WARNING: at lib/kref.c:43 kref_get+0x23/0x2b()
Jul 22 14:39:50 linux kernel: [  593.210144] Hardware name: To Be Filled By O.E.M.
Jul 22 14:39:50 linux kernel: [  593.210148] Modules linked in: powernow_k8
Jul 22 14:39:50 linux kernel: [  593.210158] Pid: 378, comm: kondemand/2 Tainted: G        W  2.6.31-rc2 #38
Jul 22 14:39:50 linux kernel: [  593.210163] Call Trace:
Jul 22 14:39:50 linux kernel: [  593.210171]  [<ffffffff812008e8>] ? kref_get+0x23/0x2b
Jul 22 14:39:50 linux kernel: [  593.210181]  [<ffffffff81041926>] warn_slowpath_common+0x77/0xa4
Jul 22 14:39:50 linux kernel: [  593.210190]  [<ffffffff81041962>] warn_slowpath_null+0xf/0x11
Jul 22 14:39:50 linux kernel: [  593.210198]  [<ffffffff812008e8>] kref_get+0x23/0x2b
Jul 22 14:39:50 linux kernel: [  593.210206]  [<ffffffff811ffa19>] kobject_get+0x1a/0x22
Jul 22 14:39:50 linux kernel: [  593.210214]  [<ffffffff813e815d>] cpufreq_cpu_get+0x8a/0xcb
Jul 22 14:39:50 linux kernel: [  593.210222]  [<ffffffff813e87d1>] __cpufreq_driver_getavg+0x1d/0x67
Jul 22 14:39:50 linux kernel: [  593.210231]  [<ffffffff813ea18f>] do_dbs_timer+0x158/0x27f
Jul 22 14:39:50 linux kernel: [  593.210240]  [<ffffffff810529ea>] worker_thread+0x200/0x313
...

The output continues on every do_dbs_timer ondemand freq checking poll.
This regression was introduced by git commit:
3f4a782b

The policy is released when the cpufreq device is removed in:
__cpufreq_remove_dev():
	/* if this isn't the CPU which is the parent of the kobj, we
	 * only need to unlink, put and exit
	 */

Not creating the symlink is not sever at all.
As long as:
sysfs_remove_link(&sys_dev->kobj, "cpufreq");
handles it gracefully that the symlink did not exist.
Possibly no error should be returned at all, because ondemand
governor would still provide the same functionality.
Userspace in userspace gov case might be confused if the link
is missing.

Resolves http://bugzilla.kernel.org/show_bug.cgi?id=13903

CC: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
CC: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Thomas Renninger <trenn@suse.de>
Signed-off-by: Dave Jones <davej@redhat.com>

Suspend/Resume fails on multi socket, multi core systems because the cpufreq
code erroneously sets the per_cpu policy_cpu value when a logical cpu is
offline.

This most notably results in missing sysfs files that are used to set the
cpu frequencies of the various cpus.
Signed-off-by: Prarit Bhargava <prarit@redhat.com>
Signed-off-by: Dave Jones <davej@redhat.com>

Commit ee88415c
introduced this regression when it removed enable bit in cpu_dbs_info_s.
That added a possibility of dbs_cpufreq_notifier getting called for a
CPU that is not yet managed by conservative governor. That will happen
as the transition notifier is set as soon as one CPU switches to
conservative governor and other CPUs can get a NULL pointer dereference
without the enable bit check. Add the enable bit back again.
Reported-by: Lermytte Christophe <Christophe.Lermytte@thomson.net>
Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Dave Jones <davej@redhat.com>

* 'for-linus' of git://neil.brown.name/md:
  md: Use revalidate_disk to effect changes in size of device.
  md: allow raid5_quiesce to work properly when reshape is happening.
  md/raid5: set reshape_position correctly when reshape starts.
  md: Handle growth of v1.x metadata correctly.
  md: avoid array overflow with bad v1.x metadata
  md: when a level change reduces the number of devices, remove the excess.
  md: Push down data integrity code to personalities.
  md/raid6: release spare page at ->stop()

As revalidate_disk calls check_disk_size_change, it will cause
any capacity change of a gendisk to be propagated to the blockdev
inode.  So use that instead of mucking about with locks and
i_size_write.

Also add a call to revalidate_disk in do_md_run and a few other places
where the gendisk capacity is changed.
Signed-off-by: NeilBrown <neilb@suse.de>

The ->quiesce method is not supposed to stop resync/recovery/reshape,
just normal IO.
But in raid5 we don't have a way to know which stripes are being
used for normal IO and which for resync etc, so we need to wait for
all stripes to be idle to be sure that all writes have completed.

However reshape keeps at least some stripe busy for an extended period
of time, so a call to raid5_quiesce can block for several seconds
needlessly.
So arrange for reshape etc to pause briefly while raid5_quiesce is
trying to quiesce the array so that the active_stripes count can
drop to zero.
Signed-off-by: NeilBrown <neilb@suse.de>

As the internal reshape_progress counter is the main driver
for reshape, the fact that reshape_position sometimes starts with the
wrong value has minimal effect.  It is visible in sysfs and that
is all.
Signed-off-by: NeilBrown <neilb@suse.de>

The v1.x metadata does not have a fixed size and can grow
when devices are added.
If it grows enough to require an extra sector of storage,
we need to update the 'sb_size' to match.

Without this, md can write out an incomplete superblock with a
bad checksum, which will be rejected when trying to re-assemble
the array.

Cc: stable@kernel.org
Signed-off-by: NeilBrown <neilb@suse.de>

We trust the 'desc_nr' field in v1.x metadata enough to use it
as an index in an array.  This isn't really safe.
So range-check the value first.
Signed-off-by: NeilBrown <neilb@suse.de>

When an array is changed from RAID6 to RAID5, fewer drives are
needed.  So any device that is made superfluous by the level
conversion must be marked as not-active.
For the RAID6->RAID5 conversion, this will be a drive which only
has 'Q' blocks on it.

Cc: stable@kernel.org
Signed-off-by: NeilBrown <neilb@suse.de>

This patch replaces md_integrity_check() by two new public functions:
md_integrity_register() and md_integrity_add_rdev() which are both
personality-independent.

md_integrity_register() is called from the ->run and ->hot_remove
methods of all personalities that support data integrity.  The
function iterates over the component devices of the array and
determines if all active devices are integrity capable and if their
profiles match. If this is the case, the common profile is registered
for the mddev via blk_integrity_register().

The second new function, md_integrity_add_rdev() is called from the
->hot_add_disk methods, i.e. whenever a new device is being added
to a raid array. If the new device does not support data integrity,
or has a profile different from the one already registered, data
integrity for the mddev is disabled.

For raid0 and linear, only the call to md_integrity_register() from
the ->run method is necessary.
Signed-off-by: Andre Noll <maan@systemlinux.org>
Signed-off-by: NeilBrown <neilb@suse.de>

* git://git.kernel.org/pub/scm/linux/kernel/git/wim/linux-2.6-watchdog:
  [WATCHDOG] Fix COH 901 327 watchdog enablement

* 'release' of git://git.kernel.org/pub/scm/linux/kernel/git/lenb/linux-acpi-2.6:
  eeepc-laptop: fix hot-unplug on resume
  ACPI: Ingore the memory block with zero block size in course of memory hotplug
  ACPI: Don't treat generic error as ACPI error code in acpi memory hotplug driver
  ACPI: bind workqueues to CPU 0 to avoid SMI corruption
  ACPI: root-only read protection on /sys/firmware/acpi/tables/*
  thinkpad-acpi: fix incorrect use of TPACPI_BRGHT_MODE_ECNVRAM
  thinkpad-acpi: restrict procfs count value to sane upper limit
  thinkpad-acpi: remove dock and bay subdrivers
  thinkpad-acpi: disable broken bay and dock subdrivers
  hp-wmi: check that an input device exists in resume handler
  Revert "ACPICA: Remove obsolete acpi_os_validate_address interface"

Clearly, I am a glutton for punishment.  I'll see if I can see Alan's
changes through to the end, otherwise I'll be fending off a lot of bug
reports for usb-serial devices.

Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

This function has traditionally used "insert_resource()", because before
commit cebd78a8 ("Fix pci_claim_resource") it used to just insert the
resource into whatever root resource tree that was indicated by
"pcibios_select_root()".

So there Matthew fixed it to actually look up the proper parent
resource, which means that now it's actively wrong to then traverse the
resource tree any more: we already know exactly where the new resource
should go.

And when we then did commit a76117df ("x86: Use pci_claim_resource"),
which changed the x86 PCI code from the open-coded

	pr = pci_find_parent_resource(dev, r);
	if (!pr || request_resource(pr, r) < 0) {

to using

	if (pci_claim_resource(dev, idx) < 0) {

that "insert_resource()" now suddenly became a problem, and causes a
regression covered by

	http://bugzilla.kernel.org/show_bug.cgi?id=13891

which this fixes.
Reported-and-tested-by: Rafael J. Wysocki <rjw@sisk.pl>
Cc: Matthew Wilcox <willy@linux.intel.com>
Cc: Andrew Patterson <andrew.patterson@hp.com>
Cc: Linux PCI <linux-pci@vger.kernel.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Since the COH 901 327 found in U300 is clocked at 32 kHz we need
to wait for the interrupt clearing flag to propagate through
hardware in order not to accidentally fire off any interrupts
when we enable them.
Signed-off-by: Linus Walleij <linus.walleij@stericsson.com>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>

OOPS on resume when the wireless adaptor is disabled during suspend was
introduced by "eeepc-laptop: read rfkill soft-blocked state on resume".

Unable to handle kernel NULL pointer dereference

Process s2disk
Tainted: G W
IP: klist_put

Call trace:
? klist_del
? device_del
? device_unregister
? pci_stop_dev
? pci_stop_bus
? pci_remove_device
? eeepc_rfkill_hotplug [eeepc_laptop]
? eeepc_hotk_resume [eeepc_laptop]
? acpi_device_resume
? device_resume
? hibernation_snapshot

It appears the PCI device is removed twice.  The eeepc_rfkill_hotplug()
call from the resume handler is racing against the call from the ACPI
notifier callback.  The ACPI notification is triggered by the resume
handler when it refreshes the value of CM_ASL_WLAN.

The fix is to serialize hotplug calls using a workqueue.

http://bugzilla.kernel.org/show_bug.cgi?id=13825Signed-off-by: Alan Jenkins <alan-jenkins@tuffmail.co.uk>
Acked-by: Corentin Chary <corentin.chary@gmail.com>
Signed-off-by: Len Brown <len.brown@intel.com>

If the memory block size is zero, ignore it and don't do the memory hotplug
flowchart. Otherwise it will complain the following warning message:
  >System RAM resource 0 - ffffffffffffffff cannot be added
Signed-off-by: Zhao Yakui <yakui.zhao@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>

Don't treat the generic error as ACPI error code. Otherwise when the generic
code is returned, it will complain the following warning messag:
   >ACPI Exception (acpi_memhotplug-0171): UNKNOWN_STATUS_CODE,
		Cannot get acpi bus device [20080609]
   >ACPI: Cannot find driver data
   > ACPI Error (utglobal-0127): Unknown exception code: 0xFFFFFFED [20080609]
   > Pid: 85, comm: kacpi_notify Not tainted 2.6.27.19-5-default #1
     Call Trace:
     [<ffffffff8020da29>] show_trace_log_lvl+0x41/0x58
     [<ffffffff8049a3da>] dump_stack+0x69/0x6f
    .....

At the same time when the generic error code is returned, the ACPI_EXCEPTION
is replaced by the printk.
Signed-off-by: Zhao Yakui <yakui.zhao@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>

On some machines, a software-initiated SMI causes corruption unless the
SMI runs on CPU 0.  An SMI can be initiated by any AML, but typically it's
done in GPE-related methods that are run via workqueues, so we can avoid
the known corruption cases by binding the workqueues to CPU 0.

References:
    http://bugzilla.kernel.org/show_bug.cgi?id=13751
    https://bugs.launchpad.net/bugs/157171
    https://bugs.launchpad.net/bugs/157691Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com>
Signed-off-by: Len Brown <len.brown@intel.com>

they were world readable.
Signed-off-by: Len Brown <len.brown@intel.com>

HBRV-based default selection of backlight control strategy didn't work
well, at least the X41 defines it but doesn't use it and I don't think
it will stop there.

Switch to a white/blacklist.  All models that have HBRV defined have
been included in the list, and initially all ATI GPUs will get
ECNVRAM, and the Intel GPUs will get UCMS_STEP.

Symptoms of incorrect backlight mode selection are:

1. Non-working backlight control through sysfs;

2. Backlight gets reset to the lowest level at every shutdown, reboot
   and when thinkpad-acpi gets unloaded;

This fixes a regression in 2.6.30, bugzilla #13826
Signed-off-by: Henrique de Moraes Holschuh <hmh@hmh.eng.br>
Reported-by: Tobias Diedrich <ranma+kernel@tdiedrich.de>
Cc: stable@kernel.org
Signed-off-by: Len Brown <len.brown@intel.com>

Signed-off-by: Michael Buesch <mb@bu3sch.de>
Acked-by: Henrique de Moraes Holschuh <hmh@hmh.eng.br>
Signed-off-by: Len Brown <len.brown@intel.com>

The standard ACPI dock driver can handle the hotplug bays and docks of
the ThinkPads just fine (including batteries) as of 2.6.27, and the
code in thinkpad-acpi for the dock and bay subdrivers is currently
broken anyway...

Userspace needs some love to support the two-stage ejection nicely,
but it is simple enough to do through udev rules (you don't even need
HAL) so this wouldn't justify fixing the dock and bay subdrivers,
either.

That leaves warm-swap bays (_EJ3) support for thinkpad-acpi, as well
as support for the weird dock of the model 570, but since such support
has never left the "experimental" stage, it is also not a strong
enough reason to find a way to fix this code.

Users of ThinkPads with warm-swap bays are urged to request that _EJ3
support be added to the regular ACPI dock driver, if such feature is
indeed useful for them.
Signed-off-by: Henrique de Moraes Holschuh <hmh@hmh.eng.br>
Signed-off-by: Len Brown <len.brown@intel.com>

Currently, the ThinkPad-ACPI bay and dock drivers are completely
broken, and cause a NULL pointer derreference in kernel mode (and,
therefore, an OOPS) when they try to issue events (i.e. on dock,
undock, bay ejection, etc).

OTOH, the standard ACPI dock driver can handle the hotplug bays and
docks of the ThinkPads just fine (including batteries) as of 2.6.27.
In fact, it does a much better job of it than thinkpad-acpi ever did.

It is just not worth the hassle to find a way to fix this crap without
breaking the (deprecated) thinkpad-acpi dock/bay ABI.  This is old,
deprecated code that sees little testing or use.

As a quick fix suitable for -stable backports, mark the thinkpad-acpi
bay and dock subdrivers as BROKEN in Kconfig.  The dead code will be
removed by a later patch.

This fixes bugzilla #13669, and should be applied to 2.6.27 and later.
Signed-off-by: Henrique de Moraes Holschuh <hmh@hmh.eng.br>
Reported-by: Joerg Platte <jplatte@naasa.net>
Cc: stable@kernel.org
Signed-off-by: Len Brown <len.brown@intel.com>

The previous commit ("do_sigaltstack: avoid copying 'stack_t' as a
structure to user space") fixed a real bug.  This one just cleans up the
copy from user space to that gcc can generate better code for it (and so
that it looks the same as the later copy back to user space).
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Ulrich Drepper correctly points out that there is generally padding in
the structure on 64-bit hosts, and that copying the structure from
kernel to user space can leak information from the kernel stack in those
padding bytes.

Avoid the whole issue by just copying the three members one by one
instead, which also means that the function also can avoid the need for
a stack frame.  This also happens to match how we copy the new structure
from user space, so it all even makes sense.

[ The obvious solution of adding a memset() generates horrid code, gcc
  does really stupid things. ]
Reported-by: Ulrich Drepper <drepper@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

* 'for-linus' of git://oss.sgi.com/xfs/xfs:
  xfs: bump up nr_to_write in xfs_vm_writepage
  xfs: reduce bmv_count in xfs_vn_fiemap

* 'for-linus' of git://git.kernel.dk/linux-2.6-block:
  io context: fix ref counting
  block: make the end_io functions be non-GPL exports
  block: fix improper kobject release in blk_integrity_unregister
  block: always assign default lock to queues
  mg_disk: Add missing ready status check on mg_write()
  mg_disk: fix issue with data integrity on error in mg_write()
  mg_disk: fix reading invalid status when use polling driver
  mg_disk: remove prohibited sleep operation

Merge branch 'timers-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip

* 'timers-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  clocksource: Save mult_orig in clocksource_disable()

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/drzeus/mmc:
  mmc: orphan subsystem
  imxmmc: Remove unnecessary semicolons
  cb710: use SG_MITER_TO_SG/SG_MITER_FROM_SG
  sdhci: use SG_MITER_TO_SG/SG_MITER_FROM_SG
  lib/scatterlist: add a flags to signalize mapping direction

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound-2.6:
  ALSA: sound/aoa: Add kmalloc NULL tests
  ALSA: hda - Increase PCM stream name buf in patch_realtek.c
  sound: mpu401.c: Buffer overflow
  sound: aedsp16: Buffer overflow
  ALSA: hda: fix out-of-bound hdmi_eld.sad[] write
  ALSA: hda - Add quirk for Dell Studio 1555