Merge tag 'phy-for-4.3' of git://git.kernel.org/pub/scm/linux/kernel/git/kishon/linux-phy into usb-next

Kishon writes:

phy: for 4.3

*) Add new NXP USB OTG PHY driver
*) Add vbus/id detection, extcon support and fixes in phy-sun4i-usb
   driver
*) Add support to use phy-sun4i-usb driver for sun8i-a23 and sun8i-a33
   SoCs
*) Other trivial code cleanups, dropping .owner assignment and constify
   phy_ops
Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>

Merge tag 'usb-ci-v4.3-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/peter.chen/usb into usb-next

Peter writes:

USB: chipidea updates for v4.3-rc1

The main changes are adding several system interfaces for
tuning performance, and each vendors can adjust them according
to their design configurations.

Others are tiny improvements, like more well siTD supports,
USB_DEVICE_A_HNP_SUPPORT supports, etc.

Felipe writes:

usb: patches for v4.3 merge window

New support for Allwinne SoC on the MUSB driver has been added to the list of
glue layers. MUSB also got support for building all DMA engines in one binary;
this will be great for distros.

DWC3 now has no trace of dev_dbg()/dev_vdbg() usage. We will rely solely on
tracing to debug DWC3. There was also a fix for memory corruption with EP0 when
maxpacket size transfers are > 512 bytes.

Robert's EP capabilities flags is making EP selection a lot simpler. UDCs are
now required to set these flags up when adding endpoints to the framework.

Other than these, we have the usual set of miscelaneous cleanups and minor
fixes.
Signed-off-by: Felipe Balbi <balbi@ti.com>

The user can adjust it through dts or platform data
Signed-off-by: Peter Chen <peter.chen@freescale.com>

It is used to override the default setting for burst size, changing
burst size takes effect only when the SBUSCFG.AHBBRST = 0.
Signed-off-by: Peter Chen <peter.chen@freescale.com>

With this setting and AHBBRST at SBUSCFG as "Incremental burst of
unspecified length", each non-burst size can be taken as single
transfer. It is benefit for non-burst size transfer.
Signed-off-by: Peter Chen <peter.chen@freescale.com>

The users can change it through dts or platform data if they
want to change the default value.
Signed-off-by: Peter Chen <peter.chen@freescale.com>

It is used to change ahb burst configuration for platforms, it is
vendor specific.
Signed-off-by: Peter Chen <peter.chen@freescale.com>

Stream mode enable is known for better performance, this stream mode
enable patch has been passed with stress tests at device mode for
imx6sl and imx6sx, and no issue is found.
Signed-off-by: Peter Chen <peter.chen@freescale.com>

The system bus and chipidea IP have different limitations for
both host and device mode.
For example, with below errata, we need to enable SDIS(Stream Disable
Mode) at host mode. But we don't want it for device mode at the
same system.

TAR 9000378958
Title: Non-Double Word Aligned Buffer Address Sometimes Causes Host to
Hang on OUT Retry
Impacted Configuration: Host mode, all transfer types
Description:
The host core operating in streaming mode may under run while sending
the data packet of an OUT transaction. This under run can occur if
there are unexpected system delays in fetching the remaining packet
data from memory. The host forces a bad CRC on the packet, the device
detects the error and discards the packet. The host then retries a Bulk,
Interrupt, or Control transfer if an under run occurs according to the
USB specification. During simulations, it was found that the host does
not issue the retry of the failed bulk OUT. It does not issue any other
transactions except SOF packets that have incorrect frame numbers.

The second failure mode occurs if the under run occurs on an ISO OUT
transaction and the next ISO transaction is a zero byte packet. The host
does not issue any transactions (including SOFs). The device detects a
Suspend condition, reverts to full speed, and waits for resume signaling.

A third failure mode occurs when the host under runs on an ISO OUT and
the next ISO in the schedule is an ISO OUT with two max packets of 1024
bytes each. The host should issue MDATA for the first OUT followed by
DATA1 for the second. However, it drops the MDATA transaction, and
issues the DATA1 transaction.

The system impact of this bug is the same regardless of the failure mode
observed. The host core hangs, the ehci_ctrl state machine waits for the
protocol engine to send the completion status for the corrupted
transaction, which never occurs. No indication is sent to the host
controller driver, no register bits change and no interrupts occur.
Eventually the requesting application times out.

Detailed internal behavior:
The EHCI control state machine (ehci_ctrl) in the DMA block is responsible
for parsing the schedules and initiating all transactions. The ehci_ctrl
state machine passes the transaction details to the protocol block by
writing the transaction information in to the TxFIFO. It then asserts
the pe_hst_run_pkt signal to inform the host protocol state machine
(pe_hst_state) that there is a packet in the TxFIFO.
A tag of 0x0 indicates a start of packet with the data providing the
following information:

35:32 Tag
31:30 Reserved
29:23 Endpoint (lowest 4 bits)
22:16 Address
15:10 Reserved
9:8 Endpoint speed
7:6 Endpoint type
5:6 Data Toggle
3:0 PID
The pe_hst_state reads the packet information and constructs the packet
and issues it to the PHY interface.
The ehci_ctrl state machine writes the start transaction information in
to the TxFIFO as 0x03002910c for the OUT packet that had the under run
error. However, it writes 0xC3002910C for the retry of the Out
transaction, which is incorrect.
The pe_hst_state enters a bus timeout state after sending the bad CRC
for the packet that under ran. It then purges any data that was back
filled in to the TxFIFO for the packet that under ran. The pe_hst_state
machine stops purging the TxFIFO when it is empty or if it reads a
location that has a tag of 0x0, indicating a start of packet command.

The pe_hst_state reads 0xC3002910C and discards it as it does not decode
to a start of packet command. It continues to purge the OUT data that
has been pre-buffered for the OUT retry . The pe_hst_state detects the
hst_packet_run signal and attempts to read the PID and address
information from the TxFIFO. This location has packet data and so does
not decode to a valid PID and so falls through to the PE_HST_SOF_LOAD
state where the frame_num_counter is updated. The frame_num_counter
is updated with the data in the TxFIFO. In this case, the data is
incorrect as the ehci_ctrl state machine did not initiate the load.
The hst_pe_state machine detects the SOF request signal and sends an
SOF with the bad frame number. Meanwhile, the ehci_ctrl state machine
waits indefinitely in the run_pkt state waiting for the completion
status from pe_hst_state machine, which will never happen.

The ISO failure case is similar except that there is no retry for ISO.
The ehci_ctrl state machine moves to the next transfer in the periodic
schedule. If the under run occurs on the last entry of the periodic
list then it moves to the Async schedule.

In the case of ISO OUT simulations, the next ISO is a zero byte OUT
and again the start of packet command gets corrupted. The TxFIFO is
empty when the hst_pe_state attempts to read the Address and PID
information as the transaction is a zero byte packet. This results
in the hst_pe_state machine staying in the GET_PID state, which means
that it does not issue any transactions (including SOFs). The device
detects a Suspend condition and reverts to full speed mode and waits
for a Resume or Reset signal.

The EHCI specification allows a Non-DoubleWord (32 bits) offset to
be used as a current offset for Buffer Pointer Page 0 of the qTD.
In Non-DoubleWord aligned cases, the core reads the packet data
from the AHB memory, performs the alignment operation before writing
it in to the TxFIFO as a 32 bit data word. An End Of Packet tag (EOP)
is written to the TxFIFO after all the packet data has been written
in to the TxFIFO. The alignment function is reset to Idle by the EOP
tag. The corruption of the start of packet command arises because the
packet buffer for the OUT transaction that under ran is not aligned
to a DoubleWord, and hence no EOP tag is written to the TxFIFO. The
alignment function is still active when the start packet information
is written in to the TxFIFO for the retry of the bulk packet or for
the next transaction in the case of an under run on an ISO. This
results in the corruption of the start tag and the transaction
information.

Click for waveform showing the command 0x 0000300291 being written in
to the TX FIFO for the Out that under ran.
Click for waveform showing the command 0xC3002910C written to the
TxFIFO instead of 0x 0000300291
Versions affected: Versions 2.10a and previous versions
How discovered: Customer simulation

Workaround:
1- The EHCI specification allows a non-DoubleWord offset to be used
as a current offset for Buffer Pointer Page 0 of the qTD. However,
if a DoubleWord offset is used then this issue does not arise.
2- Use non streaming mode to eliminate under runs.

Resolution:
The fix involves changes to the traffic state machine in the
vusb_hs_dma_traf block. The ehci_ctrl state machine updates the context
information by encoding the transaction results on the
hst_op_context_update signals at the end of a transaction. The signal
hst_op_context_update is added to the traffic state machine, and the
tx_fifo_under_ran_r signal is generated if the transaction results in
an under run error. Click for waveform

The traffic state machine then traverses to the do_eop states if the
tx_fifo_under_ran error is asserted. Thus an EOP tag is written in to
the TxFIFO as shown in this waveform .

The EOP tag resets the align state machine to the Idle state ensuring
that the next command written by the echi_ctrl state machine does not
get corrupted.

File(s) modified:
RTL code fixed: …..
Method of reproducing: This failure cannot be reproduced in the current
test bench.
Date Found: March 2010
Date Fixed: June 2010
Update information:
Added the RTL code fix
Signed-off-by: Peter Chen <peter.chen@freescale.com>

The zero-length packet is the sendor tells the receiver that there
is no more data, so it is only needed at the TX side.
Signed-off-by: Peter Chen <peter.chen@freescale.com>

The system configuration API should be called before the controller
run, otherwise, undefined results may occur. So, we override hcd
reset API, and add system configuration API after controller reset.

Cc: Li Jun <peter.chen@freescale.com>
Cc: Alan Stern <stern@rowland.harvard.edu>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Peter Chen <peter.chen@freescale.com>

If usbmisc hasn't probed yet, defer the probe.

It's not enough to check if the platform device for the OF node of the
usbmisc has been registered, but it also needs to have been probed
already before we can call imx_usbmisc_init().

This can happen if the order in which devices are probed change due to
async probing or on-demand probing of dependencies.
Signed-off-by: Tomeu Vizoso <tomeu.vizoso@collabora.com>

Add runtime pm operations for registers access to avoid system hang.
Signed-off-by: Li Jun <jun.li@freescale.com>

This makes the function hw_alloc_repmap be declared to have a return
type of void now due to this particular function never returning
a error code to its caller due to this function always running
successfully to completion nor it's caller putting the return
value into a variable in order to check if a error code is passed
from the function hw_alloc_repmap when calling this function.
Signed-off-by: Nicholas Krause <xerofoify@gmail.com>

The struct ci_hdrc is the drvdata for hcd device, so we don't
need to introduce extra ci_hdrc structure for ehci.
Signed-off-by: Peter Chen <peter.chen@freescale.com>

ITC (Interrupt Threshold Control) is used to set the maximum rate at which
the host/device controller will issue interrupts. The default value is 8 (1ms)
for it. EHCI core will modify it to 1, but device mode keeps it as default
value.

In some use cases like Android ADB, it only has one usb request for each
direction, and maximum payload data is only 4KB, so the speed is 4MB/s
at most, it needs controller to trigger interrupt as fast as possible
to increase the speed. The USB performance will be better if the interrupt
can be triggered faster.

Reduce ITC value is benefit for USB performance, but the interrupt number
is increased at the same time, it may increase cpu utilization too.
Most of use case cares about performance, but some may care about
cpu utilization, so, we leave a platform interface for user.
We set ITC as 1 (1 micro-frame) as default value which is aligned
with ehci core default value.
Signed-off-by: Peter Chen <peter.chen@freescale.com>

It is used to configure the ITC (in register USBCMD) value
for kinds of applications.
Signed-off-by: Peter Chen <peter.chen@freescale.com>

It is used to configure controller parameters according to
platform data, like speed, stream mode, etc, both host and
device's initialization need it, most of code are the
same for both roles, with this new interface, it can reduce
the duplicated code and be easy to maintain in future.
Signed-off-by: Peter Chen <peter.chen@freescale.com>

At host_stop, it will call usb_remove_hcd, and reset controller later.
Signed-off-by: Peter Chen <peter.chen@freescale.com>

We can support USB OTG 1.3 USB_DEVICE_A_HNP_SUPPORT request when
the driver supports OTG FSM mode.
Signed-off-by: Peter Chen <peter.chen@freescale.com>

For i.mx platform, set ttctrl.ttha with non-zero value only affects
sitd, and ehci core makes sure the schedule is not full when accepts
new request, so it will not occur the transaction which will acorss
the SoF.
Signed-off-by: Peter Chen <peter.chen@freescale.com>

The register of ttctrl.ttha describes like below:
- Internal TT Hub Address Representation
- RW
- Default = 0000000b
This field is used to match against the Hub Address field in QH & siTD
to determine if the packet is routed to the internal TT for directly
attached FS/LS devices. If the Hub Address in the QH or siTD does not
match this address then the packet will be broadcast on the High Speed
ports destined for a downstream High Speed hub with the address in the QH/siTD.

In silicon RTL, this entry only affects QH and siTD, and the hub.addr at
both QH and siTD are 0 in ehci core for chipidea (with hcd->has_tt = 1).

So, for QH, if the "usage_tt" flag at RTL is 0, set CI_HDRC_SET_NON_ZERO_TTHA
will not affect QH (with non-hs device); for siTD, set this flag
will change remaining space requirement for the last transaction from 1023
bytes to 188 bytes, it can increase the number of transactions within one
frame, ehci periodic schedule code will not queue the packet if the frame space
is full, so it is safe to set this flag for siTD.

With this flag, it can fix the problem Alan Stern reported below:
http://www.spinics.net/lists/linux-usb/msg123125.html
And may fix Michael Tessier's problem too.
http://www.spinics.net/lists/linux-usb/msg118679.html

CC: stern@rowland.harvard.edu
CC: michael.tessier@axiontech.ca
Signed-off-by: Peter Chen <peter.chen@freescale.com>

We want the USB fixes in here as well.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Changing the frequency of the USB clock must be done before the
PLL is powered on (prepared). This matters when the USB clock
is not setup by either boot ROM or boot loader. Reorder the
function calls to adhere to the order noted in the user manual.
Signed-off-by: Joachim Eastwood <manabian@gmail.com>
Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>

Pull input subsystem fixes from Dmitry Torokhov:
 "Just small ALPS and Elan touchpads, and other driver fixups"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input:
  Input: elantech - add special check for fw_version 0x470f01 touchpad
  Input: twl4030-vibra - fix ERROR: Bad of_node_put() warning
  Input: alps - only Dell laptops have separate button bits for v2 dualpoint sticks
  Input: axp20x-pek - add module alias
  Input: turbografx - fix potential out of bound access

Pull MIPS fixes from Ralf Baechle:
 "Another round of MIPS fixes for 4.2.  No area does particularly stand
  out but we have a two unpleasant ones:

   - Kernel ptes are marked with a global bit which allows the kernel to
     share kernel TLB entries between all processes.  For this to work
     both entries of an adjacent even/odd pte pair need to have the
     global bit set.  There has been a subtle race in setting the other
     entry's global bit since ~ 2000 but it take particularly
     pathological workloads that essentially do mostly vmalloc/vfree to
     trigger this.

     This pull request fixes the 64-bit case but leaves the case of 32
     bit CPUs with 64 bit ptes unsolved for now.  The unfixed cases
     affect hardware that is not available in the field yet.

   - Instruction emulation requires loading instructions from user space
     but the current fast but simplistic approach will fail on pages
     that are PROT_EXEC but !PROT_READ.  For this reason we temporarily
     do not permit this permission and will map pages with PROT_EXEC |
     PROT_READ.

  The remainder of this pull request is more or less across the field
  and the short log explains them well"

* 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus:
  MIPS: Make set_pte() SMP safe.
  MIPS: Replace add and sub instructions in relocate_kernel.S with addiu
  MIPS: Flush RPS on kernel entry with EVA
  Revert "MIPS: BCM63xx: Provide a plat_post_dma_flush hook"
  MIPS: BMIPS: Delete unused Kconfig symbol
  MIPS: Export get_c0_perfcount_int()
  MIPS: show_stack: Fix stack trace with EVA
  MIPS: do_mcheck: Fix kernel code dump with EVA
  MIPS: SMP: Don't increment irq_count multiple times for call function IPIs
  MIPS: Partially disable RIXI support.
  MIPS: Handle page faults of executable but unreadable pages correctly.
  MIPS: Malta: Don't reinitialise RTC
  MIPS: unaligned: Fix build error on big endian R6 kernels
  MIPS: Fix sched_getaffinity with MT FPAFF enabled
  MIPS: Fix build with CONFIG_OF=y for non OF-enabled targets
  CPUFREQ: Loongson2: Fix broken build due to incorrect include.

Pull btrfs fix from Chris Mason:
 "We have a btrfs quota regression fix.

  I merged this one on Thursday and have run it through tests against
  current master.

  Normally I wouldn't have sent this while you were finalizing rc6, but
  I'm feeding mosquitoes in the adirondacks next week, so I wanted to
  get this one out before leaving.  I'll leave longer tests running and
  check on things during the week, but I don't expect any problems"

* 'for-linus-4.2' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs:
  btrfs: qgroup: Fix a regression in qgroup reserved space.

Pull thermal management fixes from Zhang Rui:
 "Specifics:

   - fix an error that "weight_attr" sysfs attribute is not removed
     while unbinding.  From: Viresh Kumar.

   - fix power allocator governor tracing to return the real request.
     From Javi Merino.

   - remove redundant owner assignment of hisi platform thermal driver.
     From Krzysztof Kozlowski.

   - a couple of small fixes of Exynos thermal driver.  From Krzysztof
     Kozlowski and Chanwoo Choi"

* 'for-rc' of git://git.kernel.org/pub/scm/linux/kernel/git/rzhang/linux:
  thermal: Drop owner assignment from platform_driver
  thermal: exynos: Remove unused code related to platform_data on probe()
  thermal: exynos: Add the dependency of CONFIG_THERMAL_OF instead of CONFIG_OF
  thermal: exynos: Disable the regulator on probe failure
  thermal: power_allocator: trace the real requested power
  thermal: remove dangling 'weight_attr' device file

>From the usb 3.1 spec available at http://www.usb.org/developers/docs/
table 10-7 (Hub Class Requests) specifies the values for SetHubDepth and
GetPortErrorCount as:

Request			bmRequestType	bRequest		wValue		wIndex	wLength	Data
SetHubDepth		00100000B	SET_HUB_DEPTH		Hub Depth	Zero	Zero	None
GetPortErrorCount	10100011B	GET_PORT_ERR_COUNT	Zero		Port	Two	Number of Link Errors on this port

Fix these two values to match the spec.
Signed-off-by: Tal Shorer <tal.shorer@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Removed some checkpatch.pl warnings saying there was an unwanted space between
function names and their arguments.
Signed-off-by: Chase Metzger <chasemetzger15@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Fix two occurrences of the checkpatch.pl error:

ERROR: space prohibited before that ',' (ctx:WxW)

Fix one occurrence of the checkpatch error:

ERROR: space required before the open parenthesis '('
Signed-off-by: Kris Borer <kborer@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

This patch enables xhci driver to support SPC by handling
Stopped - Short Packet event in transfer event path.

If SPC = '1' and the stop endpoint command is executed, after a Short
Packet condition has been detected, but before the end of the TD has been
reached, (i.e. the TD is in progress for pipe), then a Transfer Event TRB
with its Completion Code set to Stopped - Short Packet and its TRB
Transfer Length set to value of the EDTLA shall be forced for the
interrupted TRB, irrespective of whether its IOC or ISP flags are set.
This Transfer Event TRB will precede the Command Completion Event TRB for
the command, and is referred to as a Stopped Transfer Event.
Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

If the Contiguous Frame ID Capability is supported (CFC = 1),
then the xHC shall match the Frame ID in every Isoch TD with
SIA = 0 against the Frame Index of the MFINDEX register. This
rule ensures resynchronization of Isoch TDs even if some are
dropped due to Missed Service Errors or Stopping the endpoint.

This patch enables xHCI driver to support CFC by calculating
and setting the Frame ID field of an Isoch TRB.

[made some dbg messages checkpatch friendly -Mathias]
Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

This commit checks for the URB_ZERO_PACKET flag and creates an extra
zero-length td if the urb transfer length is a multiple of the endpoint's
max packet length.
Signed-off-by: Reyad Attiyat <reyad.attiyat@gmail.com>
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Right now xhci-plat-hcd can be built when using one of platform specific
drivers only (mvebu/rcar). There shouldn't be such limitation as some
platforms may not require any quirks and may want to just use a generic
driver ("generic-xhci" / "xhci-hcd").
Signed-off-by: Rafał Miłecki <zajec5@gmail.com>
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Pull ARC fixes from Vineet Gupta:
 "Here's a late pull request for accumulated ARC fixes which came out of
  extended testing of the new ARCv2 port with LTP etc.  llock/scond
  livelock workaround has been reviewed by PeterZ.  The changes look a
  lot but I've crafted them into finer grained patches for better
  tracking later.

  I have some more fixes (ARC Futex backend) ready to go but those will
  have to wait for tglx to return from vacation.

  Summary:
   - Enable a reduced config of HS38 (w/o div-rem, ll64...)
   - Add software workaround for LLOCK/SCOND livelock
   - Fallout of a recent pt_regs update"

* tag 'arc-v4.2-rc6-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/vgupta/arc:
  ARCv2: spinlock/rwlock/atomics: reduce 1 instruction in exponential backoff
  ARC: Make pt_regs regs unsigned
  ARCv2: spinlock/rwlock: Reset retry delay when starting a new spin-wait cycle
  ARCv2: spinlock/rwlock/atomics: Delayed retry of failed SCOND with exponential backoff
  ARC: LLOCK/SCOND based rwlock
  ARC: LLOCK/SCOND based spin_lock
  ARC: refactor atomic inline asm operands with symbolic names
  Revert "ARCv2: STAR 9000837815 workaround hardware exclusive transactions livelock"
  ARCv2: [axs103_smp] Reduce clk for Quad FPGA configs
  ARCv2: Fix the peripheral address space detection
  ARCv2: allow selection of page size for MMUv4
  ARCv2: lib: memset: Don't assume 64-bit load/stores
  ARCv2: lib: memcpy: Missing PREFETCHW
  ARCv2: add knob for DIV_REV in Kconfig
  ARC/time: Migrate to new 'set-state' interface

Pull virtio fix from Michael Tsirkin:
 "A last minute fix for the new virtio input driver.  It seems pretty
   obvious, and the problem it's fixing would be quite hard to debug"

* tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost:
  virtio-input: reset device and detach unused during remove

Pull device mapper fixes from Mike Snitzer:

 - stable fix for a dm_merge_bvec() regression on 32 bit Fedora systems.

 - fix for a 4.2 DM thinp discard regression due to inability to
   properly delete a range of blocks in a data mapping btree.

* tag 'dm-4.2-fixes-4' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm:
  dm btree remove: fix bug in remove_one()
  dm: fix dm_merge_bvec regression on 32 bit systems