Currently, Mode-Control register is accessed by read-modify-write.

According to DMA hardware specifications datasheet, prohibits this method.
Because this register resets to 0 by DMA HW after DMA transfer completes.
Thus, current read-modify-write processing can cause unexpected behavior.

The datasheet says in case of writing Mode-Control register, set the value for only target channel, the others must set '11b'.
e.g. Set DMA0=01b  DMA11=10b
CTL0=33333331h
CTL2=00002333h

NOTE:
CTL0 includes DMA0~7 Mode-Control register.
CTL2 includes DMA8~11 Mode-Control register.

This patch modifies the issue.
Signed-off-by: Tomoya MORINAGA <tomoya-linux@dsn.okisemi.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

In general, the mxs-dma users get separate irq for each channel,
but gpmi is special one which has only one irq shared by all gpmi
channels.  It causes mxs_dma channel allocation function fail for
all other gpmi channels except the first one calling into the
function.

The patch gets request_irq call skipped for NO_IRQ case, and leaves
this gpmi specific quirk to gpmi driver to sort out.  It will fix
above problem if gpmi driver sets chan_irq as gpmi irq for only one
channel and NO_IRQ for all the rest channels.
Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
Cc: Vinod Koul <vinod.koul@intel.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

While testing Per Forlins MMC speed improvements I noticed a
semantic bug in the COH901318 driver: it will write to channel
registers in the prep_slave_sg() function, instead of deferring
it to later, breaking the assumption from the drivers to be able
to queue up new jobs while another job is running. Fix this by
storing up the initial register writes in the job descriptors
and write them to hardware when we process the descriptor
instead. Now the stress tests work.
Acked-by: Per Forlin <per.forlin@linaro.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

Currently the runtime config implementation forces the memory side
parameters to be the same as the peripheral side. Allow these to be
different, and check for misconfiguration.
Signed-off-by: Rabin Vincent <rabin.vincent@stericsson.com>
Reviewed-by: Ulf HANSSON <ulf.hansson@stericsson.com>
Tested-by: Stefan Nilsson <stefan.xk.nilsson@stericsson.com>
Reviewed-by: Per Forlin <per.forlin@stericsson.com>
Reviewed-by: Srinidhi Kasagar <srinidhi.kasagar@stericsson.com>
Cc: Robert Marklund <robert.marklund@stericsson.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

The DMA40 is not a PrimeCell from ARM, but it still use the same
ID registers. So let's utilize the existing macros in the
PrimeCell header to identify manufacturer and revision of the IP
block instead of reinventing the wheel.

Cc: Robert Marklund <robert.marklund@stericsson.com>
Cc: Per Forlin <per.forlin@linaro.org>
Cc: Rabin Vincent <rabin.vincent@stericsson.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

This function may be initiated from IRQ context, so the allocation
must allocate NOWAIT memory.
Signed-off-by: Robert Marklund <robert.marklund@stericsson.com>
Reviewed-by: Rabin Vincent <rabin.vincent@stericsson.com>
Reviewed-by: Philippe Langlais <philippe.langlais@stericsson.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

Missing documentation creates kernel-doc warnings, so add
the documenation.
Signed-off-by: Om Prakash <omprakash.pal@stericsson.com>
Reviewed-by: Rabin Vincent <rabin.vincent@stericsson.com>
Reviewed-by: Jonas Aberg <jonas.aberg@stericsson.com>
Reviewed-by: Srinidhi Kasagar <srinidhi.kasagar@stericsson.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

ste_dma40 now implements issue_pending according to documentation.
Submit adds descriptos to a pending queue with are flushed down to the DMAC
at issue_pending.
Signed-off-by: Per Forlin <per.forlin@linaro.org>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

tx_submit will add descriptors to the pending queue. Issue pending
will then move the pending descriptors to the transfer queue.
Signed-off-by: Per Forlin <per.forlin@linaro.org>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

Fix for the following INFO message

=================================
[ INFO: inconsistent lock state ]
2.6.39+ #89
---------------------------------
inconsistent {HARDIRQ-ON-W} -> {IN-HARDIRQ-W} usage.
rs232/822 [HC1[1]:SC0[0]:HE0:SE1] takes:
 (&(&pd_chan->lock)->rlock){?.....}, at: [<c123b9a1>] pdc_desc_get+0x16/0xab
{HARDIRQ-ON-W} state was registered at:
  [<c104fe28>] mark_irqflags+0xbd/0x11a
  [<c1050386>] __lock_acquire+0x501/0x6bb
  [<c1050945>] lock_acquire+0x63/0x7b
  [<c131c51d>] _raw_spin_lock_bh+0x43/0x51
  [<c123bee4>] pd_alloc_chan_resources+0x92/0x11e
  [<c123ad62>] dma_chan_get+0x9b/0x107
  [<c123b2d1>] __dma_request_channel+0x61/0xdc
  [<c11ba24b>] pch_request_dma+0x61/0x19e
  [<c11bb3b8>] pch_uart_startup+0x16a/0x1a2
  [<c11b8446>] uart_startup+0x87/0x147
  [<c11b9183>] uart_open+0x117/0x13e
  [<c11a5c7d>] tty_open+0x23c/0x34c
  [<c1097705>] chrdev_open+0x140/0x15f
  [<c10930a6>] __dentry_open.clone.14+0x14a/0x22b
  [<c1093dfb>] nameidata_to_filp+0x36/0x40
  [<c109f28b>] do_last+0x513/0x635
  [<c109f4af>] path_openat+0x9c/0x2aa
  [<c109f6e4>] do_filp_open+0x27/0x69
  [<c1093f02>] do_sys_open+0xfd/0x184
  [<c1093fad>] sys_open+0x24/0x2a
  [<c131d58c>] sysenter_do_call+0x12/0x32
irq event stamp: 2522
hardirqs last  enabled at (2521): [<c131ca3b>] _raw_spin_unlock_irqrestore+0x36/0x52
hardirqs last disabled at (2522): [<c131db27>] common_interrupt+0x27/0x34
softirqs last  enabled at (2354): [<c102fa11>] __do_softirq+0x10a/0x11a
softirqs last disabled at (2299): [<c10041a4>] do_softirq+0x57/0xa4

other info that might help us debug this:
2 locks held by rs232/822:
 #0:  (&tty->atomic_write_lock){+.+.+.}, at: [<c11a4b7a>] tty_write_lock+0x14/0x3c
 #1:  (&port_lock_key){-.....}, at: [<c11bad72>] pch_uart_interrupt+0x17/0x1e9

stack backtrace:
Pid: 822, comm: rs232 Not tainted 2.6.39+ #89
Call Trace:
 [<c1319f90>] ? printk+0x19/0x1b
 [<c104f893>] print_usage_bug+0x184/0x18f
 [<c104e5b1>] ? print_irq_inversion_bug+0x10e/0x10e
 [<c104f943>] mark_lock_irq+0xa5/0x1f6
 [<c104fc9c>] mark_lock+0x208/0x2d7
 [<c104fdc0>] mark_irqflags+0x55/0x11a
 [<c1050386>] __lock_acquire+0x501/0x6bb
 [<c10042ee>] ? dump_trace+0x92/0xb6
 [<c1050945>] lock_acquire+0x63/0x7b
 [<c123b9a1>] ? pdc_desc_get+0x16/0xab
 [<c131c2d0>] _raw_spin_lock+0x3e/0x4c
 [<c123b9a1>] ? pdc_desc_get+0x16/0xab
 [<c123b9a1>] pdc_desc_get+0x16/0xab
 [<c10504d8>] ? __lock_acquire+0x653/0x6bb
 [<c123bb2c>] pd_prep_slave_sg+0x7c/0x1cb
 [<c1006c3f>] ? nommu_map_sg+0x6e/0x81
 [<c11bace6>] dma_handle_tx+0x2cf/0x344
 [<c11bad72>] ? pch_uart_interrupt+0x17/0x1e9
 [<c11baebb>] pch_uart_interrupt+0x160/0x1e9
 [<c10642fb>] handle_irq_event_percpu+0x25/0x127
 [<c1064429>] handle_irq_event+0x2c/0x43
 [<c1065e0d>] ? handle_fasteoi_irq+0x84/0x84
 [<c1065eb9>] handle_edge_irq+0xac/0xce
 <IRQ>  [<c1003ecb>] ? do_IRQ+0x38/0x9d
 [<c131db2e>] ? common_interrupt+0x2e/0x34
 [<c105007b>] ? __lock_acquire+0x1f6/0x6bb
 [<c131ca3d>] ? _raw_spin_unlock_irqrestore+0x38/0x52
 [<c11b798b>] ? uart_start+0x2d/0x32
 [<c11b7998>] ? uart_flush_chars+0x8/0xa
 [<c11a7962>] ? n_tty_write+0x12c/0x1c6
 [<c1027a73>] ? try_to_wake_up+0x251/0x251
 [<c11a4d0b>] ? tty_write+0x169/0x1dc
 [<c11a7836>] ? n_tty_ioctl+0xb7/0xb7
 [<c1094841>] ? vfs_write+0x91/0x10d
 [<c11a4ba2>] ? tty_write_lock+0x3c/0x3c
 [<c1094a69>] ? sys_write+0x3e/0x63
 [<c131d58c>] ? sysenter_do_call+0x12/0x32
Signed-off-by: Alexander Stein <alexander.stein@systec-electronic.com>
Tested-by: Tomoya MORINAGA <tomoya-linux@dsn.okisemi.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Cc: Dan Williams <dan.j.williams@intel.com> (supporter:ASYNCHRONOUS TRAN...)
Cc: Vinod Koul <vinod.koul@intel.com> (supporter:DMA GENERIC OFFLO...)
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

There exist systems with multiple DMA controllers with different
capabilities. For example, on some sh-mobile / rmobile systems there are
DMA controllers, whose channels can be configured to be used with
SD- and MMC-host controllers, serial ports etc. Besides there are also
DMA controllers, that can only be used for one special function, e.g.,
for USB. In such cases the DMA client filter function can just choose
to specify to the DMA driver, which channel it needs. Then the
.device_alloc_chan_resources() method of the DMA driver will check,
whether it can provide that dunction. If not, it will fail and the loop
in __dma_request_channel() will continue to the next DMA device, until
it finds a suitable one. This works fine with just one minor glitch:
the kernel logs error messages like

dmaengine: failed to get <channel name>: (-<error code>)

after each such non-critical failure. This patch lowers priority of
this message to the debug level.
Reported-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Tested-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Tested-by: Magnus Damm <damm@opensource.se>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

The symbol 'ep93xx_dma_prep_dma_memcpy' is only used in this driver
and should be marked static.
Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Cc: Mika Westerberg <mika.westerberg@iki.fi>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Vinod Koul <vinod.koul@intel.com>
Acked-by: Mika Westerberg <mika.westerberg@iki.fi>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

This patch adds DMA support for the EP93xx SPI driver. By default the DMA is
not enabled but it can be enabled by setting ep93xx_spi_info.use_dma to true
in board configuration file.

Note that the SPI driver still uses PIO for small transfers (<= 8 bytes) for
performance reasons.
Signed-off-by: Mika Westerberg <mika.westerberg@iki.fi>
Acked-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Acked-by: Vinod Koul <vinod.koul@intel.com>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>

Since we have converted all existing users of the old DMA API to use the DMA
engine API the old code can be dropped.
Signed-off-by: Mika Westerberg <mika.westerberg@iki.fi>
Acked-by: Ryan Mallon <rmallon@gmail.com>
Acked-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Acked-by: Vinod Koul <vinod.koul@intel.com>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>

Now that we have the EP93xx DMA engine driver in place, we convert the ASoC
drivers (I2S, AC97 and PCM) to take advantage of this new API. There are no
functional changes.
Signed-off-by: Mika Westerberg <mika.westerberg@iki.fi>
Acked-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Acked-by: Liam Girdwood <lrg@ti.com>
Acked-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Acked-by: Vinod Koul <vinod.koul@intel.com>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>

Add platform support code for the new EP93xx dmaengine driver.
Signed-off-by: Mika Westerberg <mika.westerberg@iki.fi>
Signed-off-by: Ryan Mallon <rmallon@gmail.com>
Acked-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Acked-by: Vinod Koul <vinod.koul@intel.com>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>

The ep93xx DMA controller has 10 independent memory to peripheral (M2P)
channels, and 2 dedicated memory to memory (M2M) channels. M2M channels can
also be used by SPI and IDE to perform DMA transfers to/from their memory
mapped FIFOs.

This driver supports both M2P and M2M channels with DMA_SLAVE, DMA_CYCLIC and
DMA_MEMCPY (M2M only) capabilities.
Signed-off-by: Mika Westerberg <mika.westerberg@iki.fi>
Signed-off-by: Ryan Mallon <rmallon@gmail.com>
Acked-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Acked-by: Vinod Koul <vinod.koul@intel.com>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>

One new offender detected by the recently increased type checking in
platform_get_drvdata():

drivers/rtc/rtc-m41t93.c: In function ‘m41t93_remove’:
drivers/rtc/rtc-m41t93.c:192: warning: passing argument 1 of ‘platform_get_drvdata’ from incompatible pointer type

Use spi_get_drvdata() instead of platform_get_drvdata(), cfr. commit
42fea15d ("spi/rtc-{ds1390,ds3234,m41t94}:
Use spi_get_drvdata() for SPI devices")
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>

Al Viro observes that in the hugetlb case, handle_mm_fault() may return
a value of the kind ENOSPC when its caller is expecting a value of the
kind VM_FAULT_SIGBUS: fix alloc_huge_page()'s failure returns.
Signed-off-by: Hugh Dickins <hughd@google.com>
Acked-by: Al Viro <viro@zeniv.linux.org.uk>
Cc: stable@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound-2.6:
  ALSA: usb - turn off de-emphasis in s/pdif for cm6206
  ALSA: asihpi: Use angle brackets for system includes
  ALSA: fm801: add error handling if auto-detect fails
  ALSA: hda - Check pin support EAPD in ad198x_power_eapd_write
  ALSA: hda - Fix HP and Front pins of ad1988/ad1989 in ad198x_power_eapd()
  ALSA: 6fire: Don't leak firmware in error path
  ASoC: Fix wm_hubs input PGA ZC bits
  ASoC: Fix dapm_is_shared_kcontrol so everything isn't shared

* 'hwmon-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/groeck/staging:
  hwmon: (max6642): Better chip detection schema
  hwmon: (coretemp) Further relax temperature range checks
  hwmon: (coretemp) Fix TjMax detection for older CPUs
  hwmon: (coretemp) Relax target temperature range check
  hwmon: (max6642) Rename temp_fault sysfs attribute to temp2_fault

Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Vinod Koul <vinod.koul@intel.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Vinod Koul <vinod.koul@intel.com>
Cc: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Cc: Anatolij Gustschin <agust@denx.de>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

This patch adds DMA support for the EP93xx SPI driver. By default the DMA is
not enabled but it can be enabled by setting ep93xx_spi_info.use_dma to true
in board configuration file.

Note that the SPI driver still uses PIO for small transfers (<= 8 bytes) for
performance reasons.
Signed-off-by: Mika Westerberg <mika.westerberg@iki.fi>
Acked-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Cc: Grant Likely <grant.likely@secretlab.ca>
Acked-by: Grant Likely <grant.likely@secretlab.ca>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

Since we have converted all existing users of the old DMA API to use the DMA
engine API the old code can be dropped.
Signed-off-by: Mika Westerberg <mika.westerberg@iki.fi>
Acked-by: Ryan Mallon <rmallon@gmail.com>
Acked-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

Now that we have the EP93xx DMA engine driver in place, we convert the ASoC
drivers (I2S, AC97 and PCM) to take advantage of this new API. There are no
functional changes.
Signed-off-by: Mika Westerberg <mika.westerberg@iki.fi>
Acked-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Acked-by: Liam Girdwood <lrg@ti.com>
Acked-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

Add platform support code for the new EP93xx dmaengine driver.
Signed-off-by: Mika Westerberg <mika.westerberg@iki.fi>
Signed-off-by: Ryan Mallon <rmallon@gmail.com>
Acked-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

The ep93xx DMA controller has 10 independent memory to peripheral (M2P)
channels, and 2 dedicated memory to memory (M2M) channels. M2M channels can
also be used by SPI and IDE to perform DMA transfers to/from their memory
mapped FIFOs.

This driver supports both M2P and M2M channels with DMA_SLAVE, DMA_CYCLIC and
DMA_MEMCPY (M2M only) capabilities.
Signed-off-by: Mika Westerberg <mika.westerberg@iki.fi>
Signed-off-by: Ryan Mallon <rmallon@gmail.com>
Acked-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Acked-by: Vinod Koul <vinod.koul@intel.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

* 'for-linus' of git://android.git.kernel.org/kernel/tegra:
  ARM: Tegra: Harmony: Fix conflicting GPIO numbering

Currently, both the WM8903 and TPS6586x chips attempt to register with
gpiolib using the same GPIO numbers. This causes the audio driver to
fail to initialize.

To solve this, add a define to board-harmony.h for the TPS6586x, and make
board-harmony-power.c use this define, instead of directly referencing
TEGRA_NR_GPIOS.

This fixes a regression introduced by commit
6f168f2f.
ARM: tegra: harmony: initialize the TPS65862 PMIC
Signed-off-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Colin Cross <ccross@android.com>

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/btrfs-unstable: (25 commits)
  btrfs: fix uninitialized variable warning
  btrfs: add helper for fs_info->closing
  Btrfs: add mount -o inode_cache
  btrfs: scrub: add explicit plugging
  btrfs: use btrfs_ino to access inode number
  Btrfs: don't save the inode cache if we are deleting this root
  btrfs: false BUG_ON when degraded
  Btrfs: don't save the inode cache in non-FS roots
  Btrfs: make sure we don't overflow the free space cache crc page
  Btrfs: fix uninit variable in the delayed inode code
  btrfs: scrub: don't reuse bios and pages
  Btrfs: leave spinning on lookup and map the leaf
  Btrfs: check for duplicate entries in the free space cache
  Btrfs: don't try to allocate from a block group that doesn't have enough space
  Btrfs: don't always do readahead
  Btrfs: try not to sleep as much when doing slow caching
  Btrfs: kill BTRFS_I(inode)->block_group
  Btrfs: don't look at the extent buffer level 3 times in a row
  Btrfs: map the node block when looking for readahead targets
  Btrfs: set range_start to the right start in count_range_bits
  ...

Improve detection of MAX6642 by reading non existing registers (0x04, 0x06
and 0xff). Reading those registers returns the previously read value.
Signed-off-by: Per Dalen <per.dalen@appeartv.com>
[guenter.roeck@ericsson.com: added second set of register reads]
Signed-off-by: Guenter Roeck <guenter.roeck@ericsson.com>

* git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi-rc-fixes-2.6:
  [SCSI] Fix oops caused by queue refcounting failure

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6: (40 commits)
  tg3: Fix tg3_skb_error_unmap()
  net: tracepoint of net_dev_xmit sees freed skb and causes panic
  drivers/net/can/flexcan.c: add missing clk_put
  net: dm9000: Get the chip in a known good state before enabling interrupts
  drivers/net/davinci_emac.c: add missing clk_put
  af-packet: Add flag to distinguish VID 0 from no-vlan.
  caif: Fix race when conditionally taking rtnl lock
  usbnet/cdc_ncm: add missing .reset_resume hook
  vlan: fix typo in vlan_dev_hard_start_xmit()
  net/ipv4: Check for mistakenly passed in non-IPv4 address
  iwl4965: correctly validate temperature value
  bluetooth l2cap: fix locking in l2cap_global_chan_by_psm
  ath9k: fix two more bugs in tx power
  cfg80211: don't drop p2p probe responses
  Revert "net: fix section mismatches"
  drivers/net/usb/catc.c: Fix potential deadlock in catc_ctrl_run()
  sctp: stop pending timers and purge queues when peer restart asoc
  drivers/net: ks8842 Fix crash on received packet when in PIO mode.
  ip_options_compile: properly handle unaligned pointer
  iwlagn: fix incorrect PCI subsystem id for 6150 devices
  ...

With Linus' tree, today's linux-next build (powercp ppc64_defconfig)
produced this warning:

fs/btrfs/delayed-inode.c: In function 'btrfs_delayed_update_inode':
fs/btrfs/delayed-inode.c:1598:6: warning: 'ret' may be used
uninitialized in this function

Introduced by commit 16cdcec7 ("btrfs: implement delayed inode items
operation").

This fixes a bug in btrfs_update_inode(): if the returned value from
btrfs_delayed_update_inode is a nonzero garbage, inode stat data are not
updated and several call paths may hit a BUG_ON or fail with strange
code.
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: David Sterba <dsterba@suse.cz>