* 'bugfixes' of git://git.linux-nfs.org/projects/trondmy/nfs-2.6:
  NFSv4: Fix the case where NFSv4 renewal fails
  nfs: fix build error in nfsroot with initconst
  XPRTRDMA: fix client rpcrdma FRMR registration on mlx4 devices

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound-2.6:
  ALSA: hda - Add missing check of pin vref 50 and others in Realtek codecs
  ALSA: hda - Add 5stack-no-fp model for STAC927x
  ALSA: hda - Add forced codec-slots for ASUS W5Fm

* 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/davej/cpufreq:
  [CPUFREQ] powernow-k8: determine exact CPU frequency for HW Pstates
  [CPUFREQ] powernow-k8 cleanup msg if BIOS does not export ACPI _PSS cpufreq data
  [CPUFREQ] fix timer teardown in ondemand governor
  [CPUFREQ] fix timer teardown in conservative governor
  [CPUFREQ] remove rwsem lock from CPUFREQ_GOV_STOP call
  [CPUFREQ] powernow-k7 build fix when ACPI=n
  [CPUFREQ] add atom family to p4-clockmod

When KVM is loaded, and hence VT set up, the vmcall instruction in an
lguest guest causes a #GP, not #UD.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

call_usermodehelper_setup() forgot to kfree(sub_info)
when prepare_usermodehelper_creds() failed.
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6: (21 commits)
  r8169: avoid losing MSI interrupts
  tcp: tcp_vegas ssthresh bugfix
  mac8390: fix regression caused during net_device_ops conversion
  gianfar: fix BUG under load after introduction of skb recycling
  wimax/i2400m: usb: fix device reset on autosuspend while not yet idle
  RxRPC: Error handling for rxrpc_alloc_connection()
  ipv4: Fix oops with FIB_TRIE
  pktgen: do not access flows[] beyond its length
  gigaset: beyond ARRAY_SIZE of iwb->data
  IPv6: set RTPROT_KERNEL to initial route
  net: fix rtable leak in net/ipv4/route.c
  net: fix length computation in rt_check_expire()
  wireless: beyond ARRAY_SIZE of intf->crypto_stats
  iwlwifi: update 5000 ucode support to version 2 of API
  cfg80211: fix race between core hint and driver's custom apply
  airo: fix airo_get_encode{,ext} buffer overflow like I mean it...
  ath5k: fix interpolation with equal power levels
  iwlwifi: do not cancel delayed work inside spin_lock_irqsave
  ath5k: fix exp off-by-one when computing OFDM delta slope
  wext: verify buffer size for SIOCSIWENCODEEXT
  ...

* 'merge' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc:
  powerpc/mm: Fix broken MMU PID stealing on !SMP

* 'for-linus' of git://neil.brown.name/md:
  md: don't use locked_ioctl.
  md: don't update curr_resync_completed without also updating reshape_position.
  md: raid5: avoid sector values going negative when testing reshape progress.
  md: export 'frozen' resync state through sysfs
  md: bitmap: improve bitmap maintenance code.
  md: improve errno return when setting array_size
  md: always update level / chunk_size / layout when writing v1.x metadata.

If the asynchronous lease renewal fails (usually due to a soft timeout),
then we _must_ schedule state recovery in order to ensure that we don't
lose the lease unnecessarily or, if the lease is already lost, that we
recover the locking state promptly...
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

fix build error with latest kbuild adjustments to initconst.

The commit a447c093 ("vfs: Use
const for kernel parser table") changed:

    static match_table_t __initdata tokens = {
to
    static match_table_t __initconst tokens = {

But the missing const causes popwerpc to fail with latest
updates to __initconst like this:

fs/nfs/nfsroot.c:400: error: __setup_str_nfs_root_setup causes a section type conflict
fs/nfs/nfsroot.c:400: error: __setup_str_nfs_root_setup causes a section type conflict

The bug is only present with kbuild-next.
Following patch has been build tested.
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Cc: Steven Whitehouse <swhiteho@redhat.com>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Acked-by: Jan Beulich <jbeulich@novell.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

mlx4/connectX FRMR requires local write enable together with remote
rdma write enable. This fixes NFS/RDMA operation over the ConnectX
Infiniband HCA in the default memreg mode.
Signed-off-by: Vu Pham <vu@mellanox.com>
Signed-off-by: Tom Talpey <tmtalpey@gmail.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

Slightly modified by trenn@suse.de -> only do this on fam 10h and fam 11h.

Currently powernow-k8 determines CPU frequency from ACPI PSS objects, but
according to AMD family 11h BKDG this frequency is just a rounded value:

  "CoreFreq (MHz) = The CPU COF specified by MSRC001_00[6B:64][CpuFid]
  rounded to the nearest 100 Mhz."

As a consequnce powernow-k8 reports wrong CPU frequency on some systems,
e.g. on Turion X2 Ultra:

  powernow-k8: Found 1 AMD Turion(tm)X2 Ultra DualCore Mobile ZM-82
               processors (2 cpu cores) (version 2.20.00)
  powernow-k8:    0 : pstate 0 (2200 MHz)
  powernow-k8:    1 : pstate 1 (1100 MHz)
  powernow-k8:    2 : pstate 2 (600 MHz)

But this is wrong as frequency for Pstate2 is 550 MHz. x86info reports it
correctly:

  #x86info -a |grep Pstate
  ...
  Pstate-0: fid=e, did=0, vid=24 (2200MHz)
  Pstate-1: fid=e, did=1, vid=30 (1100MHz)
  Pstate-2: fid=e, did=2, vid=3c (550MHz) (current)

Solution is to determine the frequency directly from Pstate MSRs instead
of using rounded values from ACPI table.
Signed-off-by: Andreas Herrmann <andreas.herrmann3@amd.com>
Signed-off-by: Thomas Renninger <trenn@suse.de>
Signed-off-by: Dave Jones <davej@redhat.com>

- Make the message shorter and easier to grep for
- Use printk_once instead of WARN_ONCE (functionality of these was mixed)
Signed-off-by: Thomas Renninger <trenn@suse.de>
Cc: Langsdorf, Mark <mark.langsdorf@amd.com>
Signed-off-by: Dave Jones <davej@redhat.com>

* Rafael J. Wysocki (rjw@sisk.pl) wrote:
> This message has been generated automatically as a part of a report
> of regressions introduced between 2.6.28 and 2.6.29.
>
> The following bug entry is on the current list of known regressions
> introduced between 2.6.28 and 2.6.29.  Please verify if it still should
> be listed and let me know (either way).
>
>
> Bug-Entry	: http://bugzilla.kernel.org/show_bug.cgi?id=13186
> Subject		: cpufreq timer teardown problem
> Submitter	: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
> Date		: 2009-04-23 14:00 (24 days old)
> References	: http://marc.info/?l=linux-kernel&m=124049523515036&w=4
> Handled-By	: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
> Patch		: http://patchwork.kernel.org/patch/19754/
> 		  http://patchwork.kernel.org/patch/19753/
>

(updated changelog)

cpufreq fix timer teardown in ondemand governor

The problem is that dbs_timer_exit() uses cancel_delayed_work() when it should
use cancel_delayed_work_sync(). cancel_delayed_work() does not wait for the
workqueue handler to exit.

The ondemand governor does not seem to be affected because the
"if (!dbs_info->enable)" check at the beginning of the workqueue handler returns
immediately without rescheduling the work. The conservative governor in
2.6.30-rc has the same check as the ondemand governor, which makes things
usually run smoothly. However, if the governor is quickly stopped and then
started, this could lead to the following race :

dbs_enable could be reenabled and multiple do_dbs_timer handlers would run.
This is why a synchronized teardown is required.

The following patch applies to, at least, 2.6.28.x, 2.6.29.1, 2.6.30-rc2.

Depends on patch
cpufreq: remove rwsem lock from CPUFREQ_GOV_STOP call
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
CC: Andrew Morton <akpm@linux-foundation.org>
CC: gregkh@suse.de
CC: stable@kernel.org
CC: cpufreq@vger.kernel.org
CC: Ingo Molnar <mingo@elte.hu>
CC: rjw@sisk.pl
CC: Ben Slusky <sluskyb@paranoiacs.org>
Signed-off-by: Dave Jones <davej@redhat.com>

* Rafael J. Wysocki (rjw@sisk.pl) wrote:
> This message has been generated automatically as a part of a report
> of regressions introduced between 2.6.28 and 2.6.29.
>
> The following bug entry is on the current list of known regressions
> introduced between 2.6.28 and 2.6.29.  Please verify if it still should
> be listed and let me know (either way).
>
>
> Bug-Entry	: http://bugzilla.kernel.org/show_bug.cgi?id=13186
> Subject		: cpufreq timer teardown problem
> Submitter	: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
> Date		: 2009-04-23 14:00 (24 days old)
> References	: http://marc.info/?l=linux-kernel&m=124049523515036&w=4
> Handled-By	: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
> Patch		: http://patchwork.kernel.org/patch/19754/
> 		  http://patchwork.kernel.org/patch/19753/
>

(re-send with updated changelog)

cpufreq fix timer teardown in conservative governor

The problem is that dbs_timer_exit() uses cancel_delayed_work() when it should
use cancel_delayed_work_sync(). cancel_delayed_work() does not wait for the
workqueue handler to exit.

The ondemand governor does not seem to be affected because the
"if (!dbs_info->enable)" check at the beginning of the workqueue handler returns
immediately without rescheduling the work. The conservative governor in
2.6.30-rc has the same check as the ondemand governor, which makes things
usually run smoothly. However, if the governor is quickly stopped and then
started, this could lead to the following race :

dbs_enable could be reenabled and multiple do_dbs_timer handlers would run.
This is why a synchronized teardown is required.

Depends on patch
cpufreq: remove rwsem lock from CPUFREQ_GOV_STOP call

The following patch applies to 2.6.30-rc2. Stable kernels have a similar
issue which should also be fixed, but the code changed between 2.6.29
and 2.6.30, so this patch only applies to 2.6.30-rc.
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
CC: Andrew Morton <akpm@linux-foundation.org>
CC: gregkh@suse.de
CC: stable@kernel.org
CC: cpufreq@vger.kernel.org
CC: Ingo Molnar <mingo@elte.hu>
CC: rjw@sisk.pl
CC: Ben Slusky <sluskyb@paranoiacs.org>
Signed-off-by: Dave Jones <davej@redhat.com>

* Rafael J. Wysocki (rjw@sisk.pl) wrote:
> This message has been generated automatically as a part of a report
> of regressions introduced between 2.6.28 and 2.6.29.
>
> The following bug entry is on the current list of known regressions
> introduced between 2.6.28 and 2.6.29.  Please verify if it still should
> be listed and let me know (either way).
>
>
> Bug-Entry	: http://bugzilla.kernel.org/show_bug.cgi?id=13186
> Subject		: cpufreq timer teardown problem
> Submitter	: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
> Date		: 2009-04-23 14:00 (24 days old)
> References	: http://marc.info/?l=linux-kernel&m=124049523515036&w=4
> Handled-By	: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
> Patch		: http://patchwork.kernel.org/patch/19754/
> 		  http://patchwork.kernel.org/patch/19753/

The patches linked above depend on the following patch to remove
circular locking dependency :

cpufreq: remove rwsem lock from CPUFREQ_GOV_STOP call

(the following issue was faced when using cancel_delayed_work_sync() in the
timer teardown (which fixes a race).

* KOSAKI Motohiro (kosaki.motohiro@jp.fujitsu.com) wrote:
> Hi
>
> my box output following warnings.
> it seems regression by commit 7ccc7608b836e58fbacf65ee4f8eefa288e86fac.
>
> A: work -> do_dbs_timer()  -> cpu_policy_rwsem
> B: store() -> cpu_policy_rwsem -> cpufreq_governor_dbs() -> work
>
>

Hrm, I think it must be due to my attempt to fix the timer teardown race
in ondemand governor mixed with new locking behavior in 2.6.30-rc.

The rwlock seems to be taken around the whole call to
cpufreq_governor_dbs(), when it should be only taken around accesses to
the locked data, and especially *not* around the call to
dbs_timer_exit().

Reverting my fix attempt would put the teardown race back in place
(replacing the cancel_delayed_work_sync by cancel_delayed_work).
Instead, a proper fix would imply modifying this critical section :

cpufreq.c: __cpufreq_remove_dev()
...
        if (cpufreq_driver->target)
                __cpufreq_governor(data, CPUFREQ_GOV_STOP);

        unlock_policy_rwsem_write(cpu);

To make sure the __cpufreq_governor() callback is not called with rwsem
held. This would allow execution of cancel_delayed_work_sync() without
being nested within the rwsem.

Applies on top of the 2.6.30-rc5 tree.

Required to remove circular dep in teardown of both conservative and
ondemande governors so they can use cancel_delayed_work_sync().
CPUFREQ_GOV_STOP does not modify the policy, therefore this locking seemed
unneeded.
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
CC: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Greg KH <greg@kroah.com>
CC: Ingo Molnar <mingo@elte.hu>
CC: "Rafael J. Wysocki" <rjw@sisk.pl>
CC: Ben Slusky <sluskyb@paranoiacs.org>
CC: Chris Wright <chrisw@sous-sol.org>
CC: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Dave Jones <davej@redhat.com>

arch/x86/kernel/cpu/cpufreq/powernow-k7.c:172: warning: 'invalidate_entry' defined but not used
Reported-by: Toralf Förster <toralf.foerster@gmx.de>
Signed-off-by: Dave Jones <davej@redhat.com>

Some atom procs don't do freq scaling (such as the atom 330 on my own
littlefalls2 board). By adding the atom family here, we at least get
the benefit of passive cooling in a thermal emergency. Not sure how
to see that its actually helping any, but the driver does bind and
claim its functioning on my atom 330.
Signed-off-by: Jarod Wilson <jarod@redhat.com>
Signed-off-by: Dave Jones <davej@redhat.com>

The 8169 chip only generates MSI interrupts when all enabled event
sources are quiescent and one or more sources transition to active. If
not all of the active events are acknowledged, or a new event becomes
active while the existing ones are cleared in the handler, we will not
see a new interrupt.

The current interrupt handler masks off the Rx and Tx events once the
NAPI handler has been scheduled, which opens a race window in which we
can get another Rx or Tx event and never ACK'ing it, stopping all
activity until the link is reset (ifconfig down/up). Fix this by always
ACK'ing all event sources, and loop in the handler until we have all
sources quiescent.
Signed-off-by: David Dillow <dave@thedillows.org>
Tested-by: Michael Buesch <mb@bu3sch.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

This patch fixes ssthresh accounting issues in tcp_vegas when cwnd decreases
Signed-off-by: Doug Leith <doug.leith@nuim.ie>
Signed-off-by: David S. Miller <davem@davemloft.net>

Changeset ca17584b ("mac8390: update
to net_device_ops") broke mac8390 by adding 8390.o to the link. That
meant that lib8390.c was included twice, once in mac8390.c and once in
8390.c, subject to different macros. This patch reverts that by
avoiding the wrappers in 8390.c. They seem to be of no value since
COMPAT_NET_DEV_OPS is going away soon.

Tested with a Kinetics EtherPort card.
Signed-off-by: Finn Thain <fthain@telegraphics.com.au>
Signed-off-by: David S. Miller <davem@davemloft.net>

The recent rework of the MMU PID handling for non-hash CPUs has a
subtle bug in the !SMP "optimized" variant of the PID stealing
function.  It clears the PID in the mm context before it calls
local_flush_tlb_mm(). However, the later will not flush anything
if the PID in the context is clear...
Signed-off-by: Hideo Saito <hsaito.ppc@gmail.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

md has no need for the BKL - it does its own locking.
So md_ioctl doesn't need to be a locked_ioctl.
Signed-off-by: NeilBrown <neilb@suse.de>

In order for the metadata to always be consistent, we mustn't updated
curr_resync_completed without also updating reshape_position.

The reshape code updates both at the same time.  However since
commit 97e4f42d
the common md_do_sync will sometimes update curr_resync_completed
but is not in a position to update reshape_position.
So if MD_RECOVERY_RESHAPE is set (indicating that a reshape is
happening, so reshape_position might change), don't update
curr_resync_completed in md_do_sync, leave it to the per-personality
reshape code.
Signed-off-by: NeilBrown <neilb@suse.de>

As sector_t in unsigned, we cannot afford to let 'safepos' etc go
negative.
So replace
   a -= b;
by
   a -= min(b,a);
Signed-off-by: NeilBrown <neilb@suse.de>

The md resync engine has a 'frozen' state which ensures that
no resync/recovery.  This is used to avoid races.

Export this state through the 'sync_action' sysfs attribute
so that user-space can benefit and also avoid some races.
Signed-off-by: NeilBrown <neilb@suse.de>

The code for checking which bits in the bitmap can be cleared
has 2 problems:
 1/ it repeatedly takes and drops a spinlock, where it would make
    more sense to just hold on to it most of the time.
 2/ it doesn't make use of some opportunities to skip large sections
    of the bitmap

This patch fixes those.  It will only affect CPU consumption, not
correctness.
Signed-off-by: NeilBrown <neilb@suse.de>

Instead of always returns EINVAL if anything goes wrong
when setting the array size, add the option of
  E2BIG
if the size requested is too large.  This makes it easier
for user-space to be sure what went wrong.
Signed-off-by: NeilBrown <neilb@suse.de>

We previously didn't update these fields when writing the metadata
because they could never change.  They can now, so we better write
them.
v0.90 metadata always updated these fields.
Signed-off-by: NeilBrown <neilb@suse.de>

* 'kvm-updates/2.6.30' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
  KVM: Fix PDPTR reloading on CR4 writes
  KVM: Make paravirt tlb flush also reload the PAE PDPTRs

Merge branch 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip

* 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  x86: Remove remap percpu allocator for the time being
  x86: cpa_flush_array wbinvd should be done on all CPUs
  x86: bugfix wbinvd() model check instead of family check
  x86: introduce noxsave boot parameter
  x86, setup: revert ACPI 3 E820 extended attributes support
  x86: DMI match for the Sony VGN-Z540N as it needs BIOS reboot

The processor is documented to reload the PDPTRs while in PAE mode if any
of the CR4 bits PSE, PGE, or PAE change.  Linux relies on this
behaviour when zapping the low mappings of PAE kernels during boot.

The code already handled changes to CR4.PAE; augment it to also notice changes
to PSE and PGE.

This triggered while booting an F11 PAE kernel; the futex initialization code
runs before any CR3 reloads and writes to a NULL pointer; the futex subsystem
ended up uninitialized, killing PI futexes and pulseaudio which uses them.

Cc: stable@kernel.org
Signed-off-by: Avi Kivity <avi@redhat.com>

The paravirt tlb flush may be used not only to flush TLBs, but also
to reload the four page-directory-pointer-table entries, as it is used
as a replacement for reloading CR3.  Change the code to do the entire
CR3 reloading dance instead of simply flushing the TLB.

Cc: stable@kernel.org
Signed-off-by: Avi Kivity <avi@redhat.com>

Since commit 0fd56bb5 ("gianfar:
Add support for skb recycling"), gianfar puts skbuffs that are in
the rx ring back onto the recycle list as-is in case there was a
receive error, but this breaks the following invariant: that all
skbuffs on the recycle list have skb->data = skb->head + NET_SKB_PAD.

The RXBUF_ALIGNMENT realignment done in gfar_new_skb() will be done
twice on skbuffs recycled in this way, causing there not to be enough
room in the skb anymore to receive a full packet, eventually leading
to an skb_over_panic from gfar_clean_rx_ring() -> skb_put().

Resetting the skb->data pointer to skb->head + NET_SKB_PAD before
putting the skb back onto the recycle list restores the mentioned
invariant, and should fix this issue.
Reported-by: Michael Guntsche <mike@it-loops.com>
Tested-by: Michael Guntsche <mike@it-loops.com>
Signed-off-by: Lennert Buytenhek <buytenh@wantstofly.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

Some Realtek codecs like ALC861 seem to support only VREF50 while the
current driver assumes it's only VREF80.  Check other VREF bits to set
the correct value.
Signed-off-by: Takashi Iwai <tiwai@suse.de>

Remap percpu allocator has subtle bug when combined with page
attribute changing.  Remap percpu allocator aliases PMD pages for the
first chunk and as pageattr doesn't know about the alias it ends up
updating page attributes of the original mapping thus leaving the
alises in inconsistent state which might lead to subtle data
corruption.  Please read the following threads for more information:

  http://thread.gmane.org/gmane.linux.kernel/835783

The following is the proposed fix which teaches pageattr about percpu
aliases.

  http://thread.gmane.org/gmane.linux.kernel/837157

However, the above changes are deemed too pervasive for upstream
inclusion for 2.6.30 release, so this patch essentially disables
the remap allocator for the time being.
Signed-off-by: Tejun Heo <tj@kernel.org>
LKML-Reference: <4A1A0A27.4050301@kernel.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/suspend-2.6:
  PM: Do not hold dpm_list_mtx while disabling/enabling nonboot CPUs

The problem occurs when async_synchronize_full_domain() is called when
the async_pending list is not empty.  This will cause lowest_running()
to return the cookie of the first entry on the async_pending list, which
might be nothing at all to do with the domain being asked for and thus
cause the domain synchronization to wait for an unrelated domain.   This
can cause a deadlock if domain synchronization is used from one domain
to wait for another.

Fix by running over the async_pending list to see if any pending items
actually belong to our domain (and return their cookies if they do).
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

We shouldn't hold dpm_list_mtx while executing
[disable|enable]_nonboot_cpus(), because theoretically this may lead
to a deadlock as shown by the following example (provided by Johannes
Berg):

CPU 3       CPU 2                     CPU 1
                                      suspend/hibernate
            something:
            rtnl_lock()               device_pm_lock()
                                       -> mutex_lock(&dpm_list_mtx)

            mutex_lock(&dpm_list_mtx)

linkwatch_work
 -> rtnl_lock()
                                      disable_nonboot_cpus()
                                       -> flush CPU 3 workqueue

Fortunately, device drivers are supposed to stop any activities that
might lead to the registration of new device objects way before
disable_nonboot_cpus() is called, so it shouldn't be necessary to
hold dpm_list_mtx over the entire late part of device suspend and
early part of device resume.

Thus, during the late suspend and the early resume of devices acquire
dpm_list_mtx only when dpm_list is going to be traversed and release
it right after that.

This patch is reported to fix the regressions tracked as
http://bugzilla.kernel.org/show_bug.cgi?id=13245.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Reported-by: Miles Lane <miles.lane@gmail.com>
Tested-by: Ming Lei <tom.leiming@gmail.com>