Tracepoints with no arguments can issue two warnings:
"field" defined by not used
"ret" is uninitialized in this function
Mark field as being OK to leave unused, and initialize ret.
[ Impact: fix false positive compiler warnings. ]
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Cc: mathieu.desnoyers@polymtl.ca
LKML-Reference: <1239950139-1119-5-git-send-email-jeremy@goop.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Currently, every thing needed to read the binary output from the
ring buffers is available, with the exception of the way the ring
buffers handles itself internally.
This patch creates two special files in the debugfs/tracing/events
directory:
# cat /debug/tracing/events/header_page
field: u64 timestamp; offset:0; size:8;
field: local_t commit; offset:8; size:8;
field: char data; offset:16; size:4080;
# cat /debug/tracing/events/header_event
type : 2 bits
len : 3 bits
time_delta : 27 bits
array : 32 bits
padding : type == 0
time_extend : type == 1
data : type == 3
This is to allow a userspace app to see if the ring buffer format changes
or not.
[ Impact: allow userspace apps to know of ringbuffer format changes ]
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
The hooks in the module code for the function tracer must be called
before any of that module code runs. The function tracer hooks
modify the module (replacing calls to mcount to nops). If the code
is executed while the change occurs, then the CPU can take a GPF.
To handle the above with a bit of paranoia, I originally implemented
the hooks as calls directly from the module code.
After examining the notifier calls, it looks as though the start up
notify is called before any of the module's code is executed. This makes
the use of the notify safe with ftrace.
Only the startup notify is required to be "safe". The shutdown simply
removes the entries from the ftrace function list, and does not modify
any code.
This change has another benefit. It removes a issue with a reverse dependency
in the mutexes of ftrace_lock and module_mutex.
[ Impact: fix lock dependency bug, cleanup ]
Cc: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* 'core-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
kernel/softirq.c: fix sparse warning
rcu: Make hierarchical RCU less IPI-happy
When pr_fmt() was added to the pr_debug() code, we added it not only to the
dynamic_pr_debug() function, but also to the dynamic_dev_dbg() funciton.
However, dev_dbg() doesn't make use of pr_fmt(), so neither should
dynamic_dev_dbg().
Signed-off-by: Jason Baron <jbaron@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
pr_debug() used to produce zero code unless DEBUG was #defined. This is
now no longer the case in practice[1].
There are places where it's useful to have debugging printks, but we don't
want them to generate any code in production kernels.
So add a new macro, pr_devel(), for _devel_opment, to provide the old
semantics, ie. if the programmer doesn't explicitly enable debugging, no
code is produced.
[1]: You can turn CONFIG_DYNAMIC_DEBUG off, but it's enabled in at least
one distro kernel, so it's not really a solution.
Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Cc: Jason Baron <jbaron@redhat.com>
Cc: Greg Banks <gnb@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
V3 of the early platform driver implementation.
Platform drivers are great for embedded platforms because we can separate
driver configuration from the actual driver. So base addresses,
interrupts and other configuration can be kept with the processor or board
code, and the platform driver can be reused by many different platforms.
For early devices we have nothing today. For instance, to configure early
timers and early serial ports we cannot use platform devices. This
because the setup order during boot. Timers are needed before the
platform driver core code is available. The same goes for early printk
support. Early in this case means before initcalls.
These early drivers today have their configuration either hard coded or
they receive it using some special configuration method. This is working
quite well, but if we want to support both regular kernel modules and
early devices then we need to have two ways of configuring the same
driver. A single way would be better.
The early platform driver patch is basically a set of functions that allow
drivers to register themselves and architecture code to locate them and
probe. Registration happens through early_param(). The time for the
probe is decided by the architecture code.
See Documentation/driver-model/platform.txt for more details.
[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Magnus Damm <damm@igel.co.jp>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: Kay Sievers <kay.sievers@vrfy.org>
Cc: David Brownell <david-b@pacbell.net>
Cc: Tejun Heo <htejun@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
The legacy old IDE ioctl API for this is a bit primitive so we try
and map stuff sensibly onto it.
- Set PIO over DMA devices to report 32bit
- Add ability to change the PIO32 settings if the controller permits it
- Add that functionality into the sff drivers
- Add that functionality into the VLB legacy driver
- Turn on the 32bit PIO on the ninja32 and add support there
Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
The removal of the SAME target accidentally removed one feature that is
not available from the normal NAT targets so far, having multi-range
mappings that use the same mapping for each connection from a single
client. The current behaviour is to choose the address from the range
based on source and destination IP, which breaks when communicating
with sites having multiple addresses that require all connections to
originate from the same IP address.
Introduce a IP_NAT_RANGE_PERSISTENT option that controls whether the
destination address is taken into account for selecting addresses.
http://bugzilla.kernel.org/show_bug.cgi?id=12954
Signed-off-by: Patrick McHardy <kaber@trash.net>
In commit 364fdbc00f ("spi_mpc83xx:
rework chip selects handling"), I merged activate_cs and deactivate_cs
hooks into cs_control, but I overlooked that mpc52xx_psc_spi driver
is using these hooks too. And that resulted in the following build
failure:
CC drivers/spi/mpc52xx_psc_spi.o
drivers/spi/mpc52xx_psc_spi.c: In function 'mpc52xx_psc_spi_do_probe':
drivers/spi/mpc52xx_psc_spi.c:398: error: 'struct fsl_spi_platform_data'
has no member named 'activate_cs'
drivers/spi/mpc52xx_psc_spi.c:399: error: 'struct fsl_spi_platform_data'
has no member named 'deactivate_cs'
make[2]: *** [drivers/spi/mpc52xx_psc_spi.o] Error 1
This patch simply adds the legacy hooks back for 2.6.30, and for
2.6.31 we'll convert the driver to ->cs_control.
Reported-by: Subrata Modak <subrata@linux.vnet.ibm.com>
Signed-off-by: Anton Vorontsov <avorontsov@ru.mvista.com>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
block_write_full_page doesn't allow the caller to control what happens
when the IO is over. This adds a new call named block_write_full_page_endio
so the buffer head end_io handler can be provided by the caller.
This will be used by the ext3 data=guarded mode to do i_size updates in
a workqueue based end_io handler. end_buffer_async_write is also
exported so it can be called to do the dirty work of managing page
writeback for the higher level end_io handler.
Signed-off-by: Chris Mason <chris.mason@oracle.com>
Acked-by: Theodore Tso <tytso@mit.edu>
Acked-by: Jan Kara <jack@suse.cz>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6: (64 commits)
phylib: Fix delay argument of schedule_delayed_work
NET/ixgbe: Fix powering off during shutdown
NET/e1000e: Fix powering off during shutdown
NET/e1000: Fix powering off during shutdown
packet: avoid warnings when high-order page allocation fails
gianfar: stop send queue before resetting gianfar
myr10ge: again fix lro_gen_skb() alignment
declance: convert to net_device_ops
bfin_mac: convert to net_device_ops
au1000: convert to net_device_ops
atarilance: convert to net_device_ops
a2065: convert to net_device_ops
ixgbe: update real_num_tx_queues on changing num_rx_queues
ixgbe: fix tx queue index
Revert "rose: zero length frame filtering in af_rose.c"
sfc: Use correct macro to set event bitfield
sfc: Match calls to netif_napi_add() and netif_napi_del()
bonding: Remove debug printk
e1000/e1000: fix compile warning
ehea: Fix incomplete conversion to net_device_ops
...
It turns out that copying a 16-byte area at ~800k times a second
can be really expensive :) This patch redesigns the frags GRO
interface to avoid copying that area twice.
The two disciples of the frags interface have been converted.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
Though one can specify '-d /dev/sda1' when using blktrace, it still
traces the whole sda.
To support per-partition tracing, when we start tracing, we initialize
bt->start_lba and bt->end_lba to the start and end sector of that
partition.
Note some actions are per device, thus we don't filter 0-sector events.
The original patch and discussion can be found here:
http://marc.info/?l=linux-btrace&m=122949374214540&w=2
Signed-off-by: Shawn Du <duyuyang@gmail.com>
Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Acked-by: "Theodore Ts'o" <tytso@mit.edu>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jens Axboe <jens.axboe@oracle.com>
LKML-Reference: <49E42620.4050701@cn.fujitsu.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
The default CONFIG_BUG=n version of BUG() should incorporate an empty a
do...while statement to avoid compilation weirdness.
Signed-off-by: David Howells <dhowells@redhat.com>
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: hda - Fix the cmd cache keys for amp verbs
ALSA: add missing definitions(letters) to HD-Audio.txt
ALSA: hda - Add quirk mask for Fujitsu Amilo laptops with ALC883
[ALSA] intel8x0: add one retry to the ac97_clock measurement routine
[ALSA] intel8x0: fix wrong conditions in ac97_clock measure routine
ALSA: hda - Avoid call of snd_jack_report at release
ALSA: add private_data to struct snd_jack
ALSA: snd-usb-caiaq: rename files to remove redundant information in file pathes
ALSA: snd-usb-caiaq: clean up header includes
ALSA: sound/pci: use memdup_user()
ALSA: sound/usb: use memdup_user()
ALSA: sound/isa: use memdup_user()
ALSA: sound/core: use memdup_user()
[ALSA] intel8x0: do not use zero value from PICB register
[ALSA] intel8x0: an attempt to make ac97_clock measurement more reliable
[ALSA] pcm-midlevel: Add more strict buffer position checks based on jiffies
[ALSA] hda_intel: fix unexpected ring buffer positions
ASoC: Disable S3C64xx support in Kconfig
ASoC: magician: remove un-necessary #include of pxa-regs.h and hardware.h
* 'for-linus' of git://git.kernel.dk/linux-2.6-block: (28 commits)
cfq-iosched: add close cooperator code
cfq-iosched: log responsible 'cfqq' in idle timer arm
cfq-iosched: tweak kick logic a bit more
cfq-iosched: no need to save interrupts in cfq_kick_queue()
brd: fix cacheflushing
brd: support barriers
swap: Remove code handling bio_alloc failure with __GFP_WAIT
gfs2: Remove code handling bio_alloc failure with __GFP_WAIT
ext4: Remove code handling bio_alloc failure with __GFP_WAIT
dio: Remove code handling bio_alloc failure with __GFP_WAIT
block: Remove code handling bio_alloc failure with __GFP_WAIT
bio: add documentation to bio_alloc()
splice: add helpers for locking pipe inode
splice: remove generic_file_splice_write_nolock()
ocfs2: fix i_mutex locking in ocfs2_splice_to_file()
splice: fix i_mutex locking in generic_splice_write()
splice: remove i_mutex locking in splice_from_pipe()
splice: split up __splice_from_pipe()
block: fix SG_IO to return a proper error value
cfq-iosched: don't delay queue kick for a merged request
...
* 'merge' of git://git.kernel.org/pub/scm/linux/kernel/git/paulus/powerpc:
powerpc: pseries/dtl.c should include asm/firmware.h
powerpc: Fix data-corrupting bug in __futex_atomic_op
powerpc/pseries: Set error_state to pci_channel_io_normal in eeh_report_reset()
powerpc: Allow 256kB pages with SHMEM
powerpc: Document new FSL I2C bindings and cleanup
powerpc/mm: Fix compile warning
powerpc/85xx: TQM8548: update defconfig
powerpc/85xx: TQM8548: use proper phy-handles for enet2 and enet3
powerpc/85xx: TQM85xx: correct address of LM75 I2C device nodes
powerpc: Add support for early tlbilx opcode
powerpc: Fix tlbilx opcode
We use a static value for the number of dma_debug_entries. It can be
overwritten by a kernel command line option.
Some IOMMUs (e.g. GART) can't set an appropriate value by a kernel
command line option because they can't know such value until they
finish initializing up their hardware.
This patch adds dma_debug_resize_entries() enables IOMMUs to adjust
the number of dma_debug_entries anytime.
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Acked-by: Joerg Roedel <joerg.roedel@amd.com>
Cc: fujita.tomonori@lab.ntt.co.jp
Cc: akpm@linux-foundation.org
LKML-Reference: <20090415182234R.fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
There are lots of sequences like this, especially in splice code:
if (pipe->inode)
mutex_lock(&pipe->inode->i_mutex);
/* do something */
if (pipe->inode)
mutex_unlock(&pipe->inode->i_mutex);
so introduce helpers which do the conditional locking and unlocking.
Also replace the inode_double_lock() call with a pipe_double_lock()
helper to avoid spreading the use of this functionality beyond the
pipe code.
This patch is just a cleanup, and should cause no behavioral changes.
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Remove the now unused generic_file_splice_write_nolock() function.
It's conceptually broken anyway, because splice may need to wait for
pipe events so holding locks across the whole operation is wrong.
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Rearrange locking of i_mutex on destination and call to
ocfs2_rw_lock() so locks are only held while buffers are copied with
the pipe_to_file() actor, and not while waiting for more data on the
pipe.
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Split up __splice_from_pipe() into four helper functions:
splice_from_pipe_begin()
splice_from_pipe_next()
splice_from_pipe_feed()
splice_from_pipe_end()
splice_from_pipe_next() will wait (if necessary) for more buffers to
be added to the pipe. splice_from_pipe_feed() will feed the buffers
to the supplied actor and return when there's no more data available
(or if all of the requested data has been copied).
This is necessary so that implementations can do locking around the
non-waiting splice_from_pipe_feed().
This patch should not cause any change in behavior.
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* 'master' of git://git.alsa-project.org/alsa-kernel:
[ALSA] intel8x0: add one retry to the ac97_clock measurement routine
[ALSA] intel8x0: fix wrong conditions in ac97_clock measure routine
[ALSA] intel8x0: do not use zero value from PICB register
[ALSA] intel8x0: an attempt to make ac97_clock measurement more reliable
[ALSA] pcm-midlevel: Add more strict buffer position checks based on jiffies
[ALSA] hda_intel: fix unexpected ring buffer positions
It's a somewhat twisty maze of hints and behavioural modifiers, try
and clear it up a bit with some documentation.
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
It's used by DM and MD and generally useful, so move the bio list
helpers into bio.h.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Alasdair G Kergon <agk@redhat.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Currently there are two possible platform datas for the PXA AC97 driver:
one supported by the generic AC97 driver only which provides callbacks
to allow board-specific configuration at stream startup and teardown,
and another for pxa2xx-ac97-lib which allows configuration of the reset
GPIO for PXA2xx CPUs.
Obviously this won't actually work when using the generic AC97 driver
since the drivers will attempt to parse the platform data in both
formats. Fix this by merging the two structures.
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Acked-by: Robert Jarzmik <robert.jarzmik@free.fr>
Cc: Marek Vasut <marek.vasut@gmail.com>
Signed-off-by: Eric Miao <eric.miao@marvell.com>
Impact: clean up
Create a sub directory in include/trace called events to keep the
trace point headers in their own separate directory. Only headers that
declare trace points should be defined in this directory.
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Neil Horman <nhorman@tuxdriver.com>
Cc: Zhao Lei <zhaolei@cn.fujitsu.com>
Cc: Eduard - Gabriel Munteanu <eduard.munteanu@linux360.ro>
Cc: Pekka Enberg <penberg@cs.helsinki.fi>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Impact: fix compile error of lockdep event tracer
Ingo Molnar pointed out that the system name for the lockdep tracer was "lock"
which is used to include the event trace file name. It should be "lockdep"
Reported-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* 'drm-intel-next' of git://git.kernel.org/pub/scm/linux/kernel/git/anholt/drm-intel:
drm/i915: fix scheduling while holding the new active list spinlock
drm/i915: Allow tiling of objects with bit 17 swizzling by the CPU.
drm/i915: Correctly set the write flag for get_user_pages in pread.
drm/i915: Fix use of uninitialized var in 40a5f0de
drm/i915: indicate framebuffer restore key in SysRq help message
drm/i915: sync hdmi detection by hdmi identifier with 2D
drm/i915: Fix a mismerge of the IGD patch (new .find_pll hooks missed)
drm/i915: Implement batch and ring buffer dumping
* 'core-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
lockdep: warn about lockdep disabling after kernel taint, fix
Impact: allow modules to add TRACE_EVENTS on load
This patch adds the final hooks to allow modules to use the TRACE_EVENT
macro. A notifier and a data structure are used to link the TRACE_EVENTs
defined in the module to connect them with the ftrace event tracing system.
It also adds the necessary automated clean ups to the trace events when a
module is removed.
Cc: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Impact: makes it possible to define events in modules
The events are created by reading down the section that they are linked
in by the macros. But this is not scalable to modules. This patch converts
the manipulations to use a global link list, and on boot up it adds
the items in the section to the list.
This change will allow modules to add their tracing events to the list as
well.
Note, this change alone does not permit modules to use the TRACE_EVENT macros,
but the change is needed for them to eventually do so.
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
This patch moves the ftrace creation into include/trace/ftrace.h and
simplifies the work of developers in adding new tracepoints.
Just the act of creating the trace points in include/trace and including
define_trace.h will create the events in the debugfs/tracing/events
directory.
This patch removes the need of include/trace/trace_events.h
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
In preparation to allowing trace events to happen in modules, we need
to move some of the local declarations in the kernel/trace directory
into include/linux.
This patch simply moves the declarations and performs no context changes.
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
In the process to make TRACE_EVENT macro work for modules, the trace_seq
operations must be available for core kernel code.
These operations are quite useful and can be used for other implementations.
The main idea is that we create a trace_seq handle that acts very much
like the seq_file handle.
struct trace_seq *s = kmalloc(sizeof(*s, GFP_KERNEL);
trace_seq_init(s);
trace_seq_printf(s, "some data %d\n", variable);
printk("%s", s->buffer);
The main use is to allow a top level function call several other functions
that may store printf like data into the buffer. Then at the end, the top
level function can process all the data with any method it would like to.
It could be passed to userspace, output via printk or even use seq_file:
trace_seq_to_user(s, ubuf, cnt);
seq_puts(m, s->buffer);
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
This patch lowers the number of places a developer must modify to add
new tracepoints. The current method to add a new tracepoint
into an existing system is to write the trace point macro in the
trace header with one of the macros TRACE_EVENT, TRACE_FORMAT or
DECLARE_TRACE, then they must add the same named item into the C file
with the macro DEFINE_TRACE(name) and then add the trace point.
This change cuts out the needing to add the DEFINE_TRACE(name).
Every file that uses the tracepoint must still include the trace/<type>.h
file, but the one C file must also add a define before the including
of that file.
#define CREATE_TRACE_POINTS
#include <trace/mytrace.h>
This will cause the trace/mytrace.h file to also produce the C code
necessary to implement the trace point.
Note, if more than one trace/<type>.h is used to create the C code
it is best to list them all together.
#define CREATE_TRACE_POINTS
#include <trace/foo.h>
#include <trace/bar.h>
#include <trace/fido.h>
Thanks to Mathieu Desnoyers and Christoph Hellwig for coming up with
the cleaner solution of the define above the includes over my first
design to have the C code include a "special" header.
This patch converts sched, irq and lockdep and skb to use this new
method.
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Neil Horman <nhorman@tuxdriver.com>
Cc: Zhao Lei <zhaolei@cn.fujitsu.com>
Cc: Eduard - Gabriel Munteanu <eduard.munteanu@linux360.ro>
Cc: Pekka Enberg <penberg@cs.helsinki.fi>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
I've run into the situation where I need to use list_first_entry with
rcu-guarded list. This patch introduces this.
Also simplify list_for_each_entry_rcu() to use new list_entry_rcu()
instead of list_entry().
Signed-off-by: Jiri Pirko <jpirko@redhat.com>
Reviewed-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: dipankar@in.ibm.com
LKML-Reference: <20090414153356.GC3999@psychotron.englab.brq.redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
'777c6c5 wait: prevent exclusive waiter starvation' made
__wake_up_common() global to be used from abort_exclusive_wait().
It was needed to do a wake-up with the waitqueue lock held while
passing down a key to the wake-up function.
Since '4ede816 epoll keyed wakeups: add __wake_up_locked_key() and
__wake_up_sync_key()' there is an appropriate wrapper for this case:
__wake_up_locked_key().
Use it here and make __wake_up_common() private to the scheduler
again.
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <1239720785-19661-1-git-send-email-hannes@cmpxchg.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Added private_data and private_free fields to struct snd_jack so that
the caller can assign the data. It'll be helpful for avoiding the
double-free of the jack instance.
Signed-off-by: Takashi Iwai <tiwai@suse.de>