The vb2_thread implementation was made generic and was moved from
videobuf2-v4l2.c to videobuf2-core.c in commit af3bac1a. Unfortunately
that clearly was never tested since it broke read() causing NULL address
references.
The root cause was confused handling of vb2_buffer vs v4l2_buffer (the pb
pointer in various core functions).
The v4l2_buffer no longer exists after moving the code into the core and
it is no longer needed. However, the vb2_thread code passed a pointer to
a vb2_buffer to the core functions were a v4l2_buffer pointer was expected
and vb2_thread expected that the vb2_buffer fields would be filled in
correctly.
This is obviously wrong since v4l2_buffer != vb2_buffer. Note that the
pb pointer is a void pointer, so no type-checking took place.
This patch fixes this problem:
1) allow pb to be NULL for vb2_core_(d)qbuf. The vb2_thread code will use
a NULL pointer here since they don't care about v4l2_buffer anyway.
2) let vb2_core_dqbuf pass back the index of the received buffer. This is
all vb2_thread needs: this index is the index into the q->bufs array
and vb2_thread just gets the vb2_buffer from there.
3) the fileio->b pointer (that originally contained a v4l2_buffer) is
removed altogether since it is no longer needed.
Tested with vivid and the cobalt driver.
Cc: stable@vger.kernel.org # Kernel >= 4.3
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Reported-by: Matthias Schwarzott <zzam@gentoo.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
The handling of q->plane_sizes was wrong in vb2_core_create_bufs().
The q->plane_sizes array was global and it was overwritten by create_bufs.
So if reqbufs was called with e.g. size 100000 then q->plane_sizes[0] would
be set to 100000. If create_bufs was called afterwards with size 200000,
then q->plane_sizes[0] would be overwritten with the new value. Calling
create_bufs again for size 100000 would cause an error since 100000 is now
less than q->plane_sizes[0].
This patch fixes this problem by 1) removing q->plane_sizes and using the
vb->planes[].length field instead, and 2) by introducing a min_length field
in struct vb2_plane. This field is set to the plane size as returned by
the queue_setup op and is the minimum required plane size. So user pointers
or dmabufs should all be at least this size.
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Reported-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
This ops can never fail, so make these void functions.
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
Move things related with vb2 file I/O and vb2_thread without doing any
functional changes. After that, videobuf2-internal.h is removed because
it is not necessary any more.
Signed-off-by: Junghak Sung <jh1009.sung@samsung.com>
Signed-off-by: Geunyoung Kim <nenggun.kim@samsung.com>
Acked-by: Seung-Woo Kim <sw0312.kim@samsung.com>
Acked-by: Inki Dae <inki.dae@samsung.com>
Acked-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Hans Verkuil <hansverk@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
Add copy_timestamp to struct vb2_queue as a flag set if vb2-core should
copy timestamps.
Signed-off-by: Junghak Sung <jh1009.sung@samsung.com>
Signed-off-by: Geunyoung Kim <nenggun.kim@samsung.com>
Acked-by: Seung-Woo Kim <sw0312.kim@samsung.com>
Acked-by: Inki Dae <inki.dae@samsung.com>
Signed-off-by: Hans Verkuil <hansverk@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
Move timestamp from struct vb2_v4l2_buffer to struct vb2_buffer
for common use, and change its type to u64 in order to handling
y2038 problem. This patch also includes all device drivers' changes related to
this restructuring.
Signed-off-by: Junghak Sung <jh1009.sung@samsung.com>
Signed-off-by: Geunyoung Kim <nenggun.kim@samsung.com>
Acked-by: Seung-Woo Kim <sw0312.kim@samsung.com>
Acked-by: Inki Dae <inki.dae@samsung.com>
Signed-off-by: Hans Verkuil <hansverk@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
The queue_setup callback has a void pointer that is just for V4L2
and is the pointer to the v4l2_format struct that was passed to
VIDIOC_CREATE_BUFS. The idea was that drivers would use the information
from that struct to buffers suitable for the requested format.
After the vb2 split series this pointer is now a void pointer,
which is ugly, and the reality is that all existing drivers will
effectively just look at the sizeimage field of v4l2_format.
To make this more generic the queue_setup callback is changed:
the void pointer is dropped, instead if the *num_planes argument
is 0, then use the current format size, if it is non-zero, then
it contains the number of requested planes and the sizes array
contains the requested sizes. If either is unsupported, then return
-EINVAL, otherwise use the requested size(s).
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
Prepare to divide videobuf2
- Separate vb2 trace events from v4l2 trace event.
- Make wrapper functions that will move to v4l2-side.
- Make vb2_core_* functions that will remain in core-side.
- Add a callback function table for buffer operation which makes vb2-core
to be able to invoke a v4l2-side functions.
- Rename internal functions as vb2_*.
Signed-off-by: Junghak Sung <jh1009.sung@samsung.com>
Signed-off-by: Geunyoung Kim <nenggun.kim@samsung.com>
Acked-by: Seung-Woo Kim <sw0312.kim@samsung.com>
Acked-by: Inki Dae <inki.dae@samsung.com>
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
Replace struct v4l2_format * with void * to make queue_setup()
for common use.
And then, modify all device drivers related with this change.
Signed-off-by: Junghak Sung <jh1009.sung@samsung.com>
Signed-off-by: Geunyoung Kim <nenggun.kim@samsung.com>
Acked-by: Seung-Woo Kim <sw0312.kim@samsung.com>
Acked-by: Inki Dae <inki.dae@samsung.com>
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
[hans.verkuil@cisco.com: fix missing const in fimc-lite.c]
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
Right now, "private:" tag should be lower-case, otherwise the
scripts/kernel-doc won't do the right thing.
Also, no fields after "private:" should be documented. As we don't
want to strip the documentation, let's untag. This way, it will
be seen only at the file, and not at the DocBooks.
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
include/media/videobuf2-core.h:112: warning: No description found for parameter 'get_dmabuf'
include/media/videobuf2-core.h:146: warning: No description found for parameter 'm'
include/media/videobuf2-core.h:146: warning: Excess struct/union/enum/typedef member 'mem_offset' description in 'vb2_plane'
There are still several warnings, but those are hard to fix,
as they're actually a bug at DocBook. Those should be fixed on
separate patches.
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
Remove v4l2 stuff - v4l2_buf, v4l2_plane - from struct vb2_buffer.
Add new member variables - bytesused, length, offset, userptr, fd,
data_offset - to struct vb2_plane in order to cover all information
of v4l2_plane.
struct vb2_plane {
<snip>
unsigned int bytesused;
unsigned int length;
union {
unsigned int offset;
unsigned long userptr;
int fd;
} m;
unsigned int data_offset;
}
Replace v4l2_buf with new member variables - index, type, memory - which
are common fields for buffer management.
struct vb2_buffer {
<snip>
unsigned int index;
unsigned int type;
unsigned int memory;
unsigned int num_planes;
struct vb2_plane planes[VIDEO_MAX_PLANES];
<snip>
};
v4l2 specific fields - flags, field, timestamp, timecode,
sequence - are moved to vb2_v4l2_buffer in videobuf2-v4l2.c
struct vb2_v4l2_buffer {
struct vb2_buffer vb2_buf;
__u32 flags;
__u32 field;
struct timeval timestamp;
struct v4l2_timecode timecode;
__u32 sequence;
};
Signed-off-by: Junghak Sung <jh1009.sung@samsung.com>
Signed-off-by: Geunyoung Kim <nenggun.kim@samsung.com>
Acked-by: Seung-Woo Kim <sw0312.kim@samsung.com>
Acked-by: Inki Dae <inki.dae@samsung.com>
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
Make videobuf2-v4l2 as a wrapper of videobuf2-core for v4l2-use.
And replace videobuf2-core.h with videobuf2-v4l2.h.
This renaming change should be accompanied by the modifications
of all device drivers that include videobuf2-core.h.
It can be done with just running this shell script.
replace()
{
str1=$1
str2=$2
dir=$3
for file in $(find $dir -name *.h -o -name *.c -o -name Makefile)
do
echo $file
sed "s/$str1/$str2/g" $file > $file.out
mv $file.out $file
done
}
replace "videobuf2-core" "videobuf2-v4l2" "include/media/"
replace "videobuf2-core" "videobuf2-v4l2" "drivers/media/"
replace "videobuf2-core" "videobuf2-v4l2" "drivers/usb/gadget/"
replace "videobuf2-core" "videobuf2-v4l2" "drivers/staging/media/"
Signed-off-by: Junghak Sung <jh1009.sung@samsung.com>
Signed-off-by: Geunyoung Kim <nenggun.kim@samsung.com>
Acked-by: Seung-Woo Kim <sw0312.kim@samsung.com>
Acked-by: Inki Dae <inki.dae@samsung.com>
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
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Merge tag 'media/v4.3-1' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media
Pull media updates from Mauro Carvalho Chehab:
- new DVB frontend drivers: ascot2e, cxd2841er, horus3a, lnbh25
- new HDMI capture driver: tc358743
- new driver for NetUP DVB new boards (netup_unidvb)
- IR support for DVBSky cards (smipcie-ir)
- Coda driver has gain macroblock tiling support
- Renesas R-Car gains JPEG codec driver
- new DVB platform driver for STi boards: c8sectpfe
- added documentation for the media core kABI to device-drivers DocBook
- lots of driver fixups, cleanups and improvements
* tag 'media/v4.3-1' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media: (297 commits)
[media] c8sectpfe: Remove select on undefined LIBELF_32
[media] i2c: fix platform_no_drv_owner.cocci warnings
[media] cx231xx: Use wake_up_interruptible() instead of wake_up_interruptible_nr()
[media] tc358743: only queue subdev notifications if devnode is set
[media] tc358743: add missing Kconfig dependency/select
[media] c8sectpfe: Use %pad to print 'dma_addr_t'
[media] DocBook media: Fix typo "the the" in xml files
[media] tc358743: make reset gpio optional
[media] tc358743: set direction of reset gpio using devm_gpiod_get
[media] dvbdev: document most of the functions/data structs
[media] dvb_frontend.h: document the struct dvb_frontend
[media] dvb-frontend.h: document struct dtv_frontend_properties
[media] dvb-frontend.h: document struct dvb_frontend_ops
[media] dvb: Use DVBFE_ALGO_HW where applicable
[media] dvb_frontend.h: document struct analog_demod_ops
[media] dvb_frontend.h: Document struct dvb_tuner_ops
[media] Docbook: Document struct analog_parameters
[media] dvb_frontend.h: get rid of dvbfe_modcod
[media] add documentation for struct dvb_tuner_info
[media] dvb_frontend: document dvb_frontend_tune_settings
...
Most of the stuff at videobuf2-core are ok for adding it to
DocBook.
Two notes here:
1) As videobuf2-core will be soon be changed, better to
not spend too much efforts right now, as things will
change soon;
2) struct vb2_queue has a number of private elements that are
documented. As Kernel nano documentation format handles
"private:" arguments, we need to put them on a separate
comment block or to remove. Keeping the comments is
obviously better ;)
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
Acked-by: Jonathan Corbet <corbet@lwn.net>
Buffers can be returned back to videobuf2 in driver's streamon handler. In
this case vb2_buffer_done() with buffer state VB2_BUF_STATE_QUEUED will
cause the driver's buf_queue vb2 operation to be called, queueing the same
buffer again only to be returned to videobuf2 using vb2_buffer_done() and so
on.
Add a new buffer state VB2_BUF_STATE_REQUEUEING which, when used as the
state argument to vb2_buffer_done(), will result in buffers queued to the
driver. Using VB2_BUF_STATE_QUEUED will leave the buffer to videobuf2, as it
was before "[media] vb2: allow requeuing buffers while streaming".
Fixes: ce0eff016f ("[media] vb2: allow requeuing buffers while streaming")
[mchehab@osg.samsung.com: fix warning: enumeration value 'VB2_BUF_STATE_REQUEUEING' not handled in switch]
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Acked-by: Hans Verkuil <hans.verkuil@cisco.com>
Cc: stable@vger.kernel.org # for v4.1
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
If the last buffer was dequeued from a capture queue, let poll return
immediately and let DQBUF return -EPIPE to signal there will no more
buffers to dequeue until STREAMOFF.
The driver signals the last buffer by setting the V4L2_BUF_FLAG_LAST.
To reenable dequeuing on the capture queue, the driver must explicitly
call vb2_clear_last_buffer_queued. The last buffer queued flag is
cleared automatically during STREAMOFF.
Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
Acked-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Kamil Debski <k.debski@samsung.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
The vb2: fix bytesused == 0 handling (8a75ffb) patch changed the behavior
of __fill_vb2_buffer function, so that if bytesused is 0 it is set to the
size of the buffer. However, bytesused set to 0 is used by older codec
drivers as as indication used to mark the end of stream.
To keep backward compatibility, this patch adds a flag passed to the
vb2_queue_init function - allow_zero_bytesused. If the flag is set upon
initialization of the queue, the videobuf2 keeps the value of bytesused
intact in the OUTPUT queue and passes it to the driver.
Reported-by: Nicolas Dufresne <nicolas.dufresne@collabora.com>
Signed-off-by: Kamil Debski <k.debski@samsung.com>
Acked-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
This patch splits the io_flags member of vb2_queue into a bit field.
Instead of an enum with flags separate bit fields were introduced.
Signed-off-by: Kamil Debski <k.debski@samsung.com>
Acked-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
This is needed for the next patch where the dma-sg alloc memop needs
to know the dma_dir.
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Acked-by: Pawel Osciak <pawel@osciak.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
The 'write' argument is very ambiguous. I first assumed that if it is 1,
then we're doing video output but instead it meant the reverse.
Since it is used to setup the dma_dir value anyway it is now replaced by
the correct dma_dir value which is unambiguous.
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Acked-by: Pawel Osciak <pawel@osciak.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
Document that drivers can access/modify the buffer contents in buf_prepare
and buf_finish. That was not clearly stated before.
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Acked-by: Pawel Osciak <pawel@osciak.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
The buffer flags are incorrectly referred to as V4L2_BUF_FLAGS_* instead
of V4L2_BUF_FLAG_* in comments. Fix it.
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Acked-by: Marek Szyprowski <m.szyprowski@samsung.com>
Acked-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
The recent conversion of saa7134 to vb2 unconvered a poll() bug that
broke the teletext applications alevt and mtt. These applications
expect that calling poll() without having called VIDIOC_STREAMON will
cause poll() to return POLLERR. That did not happen in vb2.
This patch fixes that behavior. It also fixes what should happen when
poll() is called when STREAMON is called but no buffers have been
queued. In that case poll() will also return POLLERR, but only for
capture queues since output queues will always return POLLOUT
anyway in that situation.
This brings the vb2 behavior in line with the old videobuf behavior.
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
The comment for start_streaming that tells the developer with which vb2 state
buffers should be returned to vb2 gave the wrong state. Very confusing.
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
this patch adds a helper to get the status if start_streaming()
was called successfully.
Signed-off-by: Lad, Prabhakar <prabhakar.csengg@gmail.com>
Cc: Pawel Osciak <pawel@osciak.com>
Cc: Marek Szyprowski <m.szyprowski@samsung.com>
Cc: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
The following lockdep warning has been there ever since commit a517cca6b2
one year ago:
[ 403.117947] ======================================================
[ 403.117949] [ INFO: possible circular locking dependency detected ]
[ 403.117953] 3.16.0-rc6-test-media #961 Not tainted
[ 403.117954] -------------------------------------------------------
[ 403.117956] v4l2-ctl/15377 is trying to acquire lock:
[ 403.117959] (&dev->mutex#3){+.+.+.}, at: [<ffffffffa005a6c3>] vb2_fop_mmap+0x33/0x90 [videobuf2_core]
[ 403.117974]
[ 403.117974] but task is already holding lock:
[ 403.117976] (&mm->mmap_sem){++++++}, at: [<ffffffff8118291f>] vm_mmap_pgoff+0x6f/0xc0
[ 403.117987]
[ 403.117987] which lock already depends on the new lock.
[ 403.117987]
[ 403.117990]
[ 403.117990] the existing dependency chain (in reverse order) is:
[ 403.117992]
[ 403.117992] -> #1 (&mm->mmap_sem){++++++}:
[ 403.117997] [<ffffffff810d733c>] validate_chain.isra.39+0x5fc/0x9a0
[ 403.118006] [<ffffffff810d8bc3>] __lock_acquire+0x4d3/0xd30
[ 403.118010] [<ffffffff810d9da7>] lock_acquire+0xa7/0x160
[ 403.118014] [<ffffffff8118c9ec>] might_fault+0x7c/0xb0
[ 403.118018] [<ffffffffa0028a25>] video_usercopy+0x425/0x610 [videodev]
[ 403.118028] [<ffffffffa0028c25>] video_ioctl2+0x15/0x20 [videodev]
[ 403.118034] [<ffffffffa0022764>] v4l2_ioctl+0x184/0x1a0 [videodev]
[ 403.118040] [<ffffffff811d77d0>] do_vfs_ioctl+0x2f0/0x4f0
[ 403.118307] [<ffffffff811d7a51>] SyS_ioctl+0x81/0xa0
[ 403.118311] [<ffffffff8199dc69>] system_call_fastpath+0x16/0x1b
[ 403.118319]
[ 403.118319] -> #0 (&dev->mutex#3){+.+.+.}:
[ 403.118324] [<ffffffff810d6a96>] check_prevs_add+0x746/0x9f0
[ 403.118329] [<ffffffff810d733c>] validate_chain.isra.39+0x5fc/0x9a0
[ 403.118333] [<ffffffff810d8bc3>] __lock_acquire+0x4d3/0xd30
[ 403.118336] [<ffffffff810d9da7>] lock_acquire+0xa7/0x160
[ 403.118340] [<ffffffff81999664>] mutex_lock_interruptible_nested+0x64/0x640
[ 403.118344] [<ffffffffa005a6c3>] vb2_fop_mmap+0x33/0x90 [videobuf2_core]
[ 403.118349] [<ffffffffa0022122>] v4l2_mmap+0x62/0xa0 [videodev]
[ 403.118354] [<ffffffff81197270>] mmap_region+0x3d0/0x5d0
[ 403.118359] [<ffffffff8119778d>] do_mmap_pgoff+0x31d/0x400
[ 403.118363] [<ffffffff81182940>] vm_mmap_pgoff+0x90/0xc0
[ 403.118366] [<ffffffff81195cef>] SyS_mmap_pgoff+0x1df/0x2a0
[ 403.118369] [<ffffffff810085c2>] SyS_mmap+0x22/0x30
[ 403.118376] [<ffffffff8199dc69>] system_call_fastpath+0x16/0x1b
[ 403.118381]
[ 403.118381] other info that might help us debug this:
[ 403.118381]
[ 403.118383] Possible unsafe locking scenario:
[ 403.118383]
[ 403.118385] CPU0 CPU1
[ 403.118387] ---- ----
[ 403.118388] lock(&mm->mmap_sem);
[ 403.118391] lock(&dev->mutex#3);
[ 403.118394] lock(&mm->mmap_sem);
[ 403.118397] lock(&dev->mutex#3);
[ 403.118400]
[ 403.118400] *** DEADLOCK ***
[ 403.118400]
[ 403.118403] 1 lock held by v4l2-ctl/15377:
[ 403.118405] #0: (&mm->mmap_sem){++++++}, at: [<ffffffff8118291f>] vm_mmap_pgoff+0x6f/0xc0
[ 403.118411]
[ 403.118411] stack backtrace:
[ 403.118415] CPU: 0 PID: 15377 Comm: v4l2-ctl Not tainted 3.16.0-rc6-test-media #961
[ 403.118418] Hardware name: VMware, Inc. VMware Virtual Platform/440BX Desktop Reference Platform, BIOS 6.00 07/31/2013
[ 403.118420] ffffffff82a6c9d0 ffff8800af37fb00 ffffffff819916a2 ffffffff82a6c9d0
[ 403.118425] ffff8800af37fb40 ffffffff810d5715 ffff8802308e4200 0000000000000000
[ 403.118429] ffff8802308e4a48 ffff8802308e4a48 ffff8802308e4200 0000000000000001
[ 403.118433] Call Trace:
[ 403.118441] [<ffffffff819916a2>] dump_stack+0x4e/0x7a
[ 403.118445] [<ffffffff810d5715>] print_circular_bug+0x1d5/0x2a0
[ 403.118449] [<ffffffff810d6a96>] check_prevs_add+0x746/0x9f0
[ 403.118455] [<ffffffff8119c172>] ? find_vmap_area+0x42/0x70
[ 403.118459] [<ffffffff810d733c>] validate_chain.isra.39+0x5fc/0x9a0
[ 403.118463] [<ffffffff810d8bc3>] __lock_acquire+0x4d3/0xd30
[ 403.118468] [<ffffffff810d9da7>] lock_acquire+0xa7/0x160
[ 403.118472] [<ffffffffa005a6c3>] ? vb2_fop_mmap+0x33/0x90 [videobuf2_core]
[ 403.118476] [<ffffffffa005a6c3>] ? vb2_fop_mmap+0x33/0x90 [videobuf2_core]
[ 403.118480] [<ffffffff81999664>] mutex_lock_interruptible_nested+0x64/0x640
[ 403.118484] [<ffffffffa005a6c3>] ? vb2_fop_mmap+0x33/0x90 [videobuf2_core]
[ 403.118488] [<ffffffffa005a6c3>] ? vb2_fop_mmap+0x33/0x90 [videobuf2_core]
[ 403.118493] [<ffffffff810d8055>] ? mark_held_locks+0x75/0xa0
[ 403.118497] [<ffffffffa005a6c3>] vb2_fop_mmap+0x33/0x90 [videobuf2_core]
[ 403.118502] [<ffffffffa0022122>] v4l2_mmap+0x62/0xa0 [videodev]
[ 403.118506] [<ffffffff81197270>] mmap_region+0x3d0/0x5d0
[ 403.118510] [<ffffffff8119778d>] do_mmap_pgoff+0x31d/0x400
[ 403.118513] [<ffffffff81182940>] vm_mmap_pgoff+0x90/0xc0
[ 403.118517] [<ffffffff81195cef>] SyS_mmap_pgoff+0x1df/0x2a0
[ 403.118521] [<ffffffff810085c2>] SyS_mmap+0x22/0x30
[ 403.118525] [<ffffffff8199dc69>] system_call_fastpath+0x16/0x1b
The reason is that vb2_fop_mmap and vb2_fop_get_unmapped_area take the core lock
while they are called with the mmap_sem semaphore held. But elsewhere in the code
the core lock is taken first but calls to copy_to/from_user() can take the mmap_sem
semaphore as well, potentially causing a classical A-B/B-A deadlock.
However, the mmap/get_unmapped_area calls really shouldn't take the core lock
at all. So what would happen if they don't take the core lock anymore?
There are two situations that need to be taken into account: calling mmap while
new buffers are being added and calling mmap while buffers are being deleted.
The first case works almost fine without a lock: in all cases mmap relies on
correctly filled-in q->num_buffers/q->num_planes values and those are only
updated by reqbufs and create_buffers *after* any new buffers have been
initialized completely. Except in one case: if an error occurred while allocating
the buffers it will increase num_buffers and rely on __vb2_queue_free to
decrease it again. So there is a short period where the buffer information
may be wrong.
The second case definitely does pose a problem: buffers may be in the process
of being deleted, without the internal structure being updated.
In order to fix this a new mutex is added to vb2_queue that is taken when
buffers are allocated or deleted, and in vb2_mmap. That way vb2_mmap won't
get stale buffer data. Note that this is a problem only for MEMORY_MMAP, so
even though __qbuf_userptr and __qbuf_dmabuf also mess around with buffers
(mem_priv in particular), this doesn't clash with vb2_mmap or
vb2_get_unmapped_area since those are MMAP specific.
As an additional bonus the hack in __buf_prepare, the USERPTR case, can be
removed as well since mmap() no longer takes the core lock.
All in all a much cleaner solution.
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Acked-by: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>
A lot of work was done in vb2 to regulate how drivers and the vb2 core handle
buffer ownership, but inexplicably the videobuf2-core.h comments were never
updated. Do so now. The same was true for the replacement of the -ENOBUFS
mechanism by the min_buffers_needed field.
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>
When a fatal error occurs that render the device unusable, the only
options for a driver to signal the error condition to userspace is to
set the V4L2_BUF_FLAG_ERROR flag when dequeuing buffers and to return an
error from the buffer prepare handler when queuing buffers.
The buffer error flag indicates a transient error and can't be used by
applications to detect fatal errors. Returning an error from vb2_qbuf()
is thus the only real indication that a fatal error occurred. However,
this is difficult to handle for multithreaded applications that requeue
buffers from a thread other than the control thread. In particular the
poll() call in the control thread will not notify userspace of the
error.
This patch adds an explicit mechanism to report fatal errors to
userspace. Drivers can call the vb2_queue_error() function to signal a
fatal error. From this moment on, buffer preparation will return -EIO to
userspace, and vb2_poll() will set the POLLERR flag and return
immediately. The error flag is cleared when cancelling the queue, either
at stream off time (through vb2_streamoff) or when releasing the queue
with vb2_queue_release().
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Acked-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>
When suspending a device while a video stream is active all buffers
marked as done but not dequeued yet will be kept across suspend and
given back to userspace after resume. This will result in outdated
buffers being dequeued.
Introduce a new vb2 function to mark all done buffers as erroneous
instead, to be used by drivers at resume time.
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Acked-by: Hans Verkuil <hans.verkuil@cisco.com>
Acked-by: Sakari Ailus <sakari.ailus@iki.fi>
Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>
The vb2 core ignores any return code from the stop_streaming op.
And there really isn't anything it can do anyway in case of an error.
So change the return type to void and update any drivers that implement it.
The int return gave drivers the idea that this operation could actually
fail, but that's really not the case.
The pwc amd sdr-msi3101 drivers both had this construction:
if (mutex_lock_interruptible(&s->v4l2_lock))
return -ERESTARTSYS;
This has been updated to just call mutex_lock(). The stop_streaming op
expects this to really stop streaming and I very much doubt this will
work reliably if stop_streaming just returns without really stopping the
DMA.
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Acked-by: Pawel Osciak <pawel@osciak.com>
Acked-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>
In order to implement vb2 DVB support you need to be able to start
a kernel thread that queues and dequeues buffers, calling a callback
function for every buffer. This patch adds support for that.
It's based on drivers/media/v4l2-core/videobuf-dvb.c, but with all the DVB
specific stuff stripped out, thus making it much more generic.
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>
Added a vb2_fileio_is_active inline function that returns true if fileio
is in progress. Check for this too in mmap() (you don't want apps mmap()ing
buffers used by fileio) and expbuf() (same reason).
In addition drivers should be able to check for this in queue_setup() to
return an error if an attempt is made to read() or write() with
V4L2_FIELD_ALTERNATE being configured. This is illegal (there is no way
to pass the TOP/BOTTOM information around using file I/O).
However, in order to be able to check for this the init_fileio function
needs to set q->fileio early on, before the buffers are allocated. So switch
to using internal functions (__reqbufs, vb2_internal_qbuf and
vb2_internal_streamon) to skip the fileio check. Well, that's why the internal
functions were created...
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Acked-by: Pawel Osciak <pawel@osciak.com>
Acked-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>
In commit 02f142ecd2 support was added to
start_streaming to return -ENOBUFS if insufficient buffers were queued
for the DMA engine to start. The vb2 core would attempt calling
start_streaming again if another buffer would be queued up.
Later analysis uncovered problems with the queue management if start_streaming
would return an error: the buffers are enqueued to the driver before the
start_streaming op is called, so after an error they are never returned to
the vb2 core. The solution for this is to let the driver return them to
the vb2 core in case of an error while starting the DMA engine. However,
in the case of -ENOBUFS that would be weird: it is not a real error, it
just says that more buffers are needed. Requiring start_streaming to give
them back only to have them requeued again the next time the application
calls QBUF is inefficient.
This patch changes this mechanism: it adds a 'min_buffers_needed' field
to vb2_queue that drivers can set with the minimum number of buffers
required to start the DMA engine. The start_streaming op is only called
if enough buffers are queued. The -ENOBUFS handling has been dropped in
favor of this new method.
Drivers are expected to return buffers back to vb2 core with state QUEUED
if start_streaming would return an error. The vb2 core checks for this
and produces a warning if that didn't happen and it will forcefully
reclaim such buffers to ensure that the internal vb2 core state remains
consistent and all buffer-related resources have been correctly freed
and all op calls have been balanced.
__reqbufs() has been updated to check that at least min_buffers_needed
buffers could be allocated. If fewer buffers were allocated then __reqbufs
will free what was allocated and return -ENOMEM. Based on a suggestion from
Pawel Osciak.
__create_bufs() doesn't do that check, since the use of __create_bufs
assumes some advance scenario where the user might want more control.
Instead streamon will check if enough buffers were allocated to prevent
streaming with fewer than the minimum required number of buffers.
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>
'queued_count' is a bit vague since it is not clear to which queue it
refers to: the vb2 internal list of buffers or the driver-owned list
of buffers.
Rename to make it explicit.
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Acked-by: Pawel Osciak <pawel@osciak.com>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>
Sometimes sentences in comments ended with a period, and sometimes they
didn't. Add periods. No other changes.
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>
If a queue was canceled, then the buf_finish op was never called for the
pending buffers. So add this call to queue_cancel. Before calling buf_finish
set the buffer state to PREPARED, which is the correct state. That way the
states DONE and ERROR will only be seen in buf_finish if streaming is in
progress.
Since buf_finish can now be called from non-streaming state we need to
adapt the handful of drivers that actually need to know this.
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Acked-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>
The buf_finish op should always work, so change the return type to void.
Update the few drivers that use it.
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Acked-by: Pawel Osciak <pawel@osciak.com>
Reviewed-by: Pawel Osciak <pawel@osciak.com>
Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>
When a vb2_queue is freed check if all the mem_ops and queue ops were balanced.
So the number of calls to e.g. buf_finish has to match the number of calls to
buf_prepare, etc.
This code is only enabled if CONFIG_VIDEO_ADV_DEBUG is set.
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Acked-by: Pawel Osciak <pawel@osciak.com>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>
Some devices do not produce timestamps that correspond to the end of the
frame. The user space should be informed on the matter. This patch achieves
that by adding buffer flags (and a mask) for timestamp sources since more
possible timestamping points are expected than just two.
A three-bit mask is defined (V4L2_BUF_FLAG_TSTAMP_SRC_MASK) and two of the
eight possible values is are defined V4L2_BUF_FLAG_TSTAMP_SRC_EOF for end of
frame (value zero) V4L2_BUF_FLAG_TSTAMP_SRC_SOE for start of exposure (next
value).
Signed-off-by: Sakari Ailus <sakari.ailus@iki.fi>
Acked-by: Kamil Debski <k.debski@samsung.com>
Acked-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>
The timestamp_type field used to contain only the timestamp type. Soon it
will be used for timestamp source flags as well. Rename the field
accordingly.
[m.chehab@samsung.com: do the change also to drivers/staging/media and at s2255]
Signed-off-by: Sakari Ailus <sakari.ailus@iki.fi>
Acked-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>
If start_streaming returns -ENOBUFS, then it will be retried the next time
a buffer is queued. This means applications no longer need to know how many
buffers need to be queued before STREAMON can be called. This is particularly
useful for output stream I/O.
If a DMA engine needs at least X buffers before it can start streaming, then
for applications to get a buffer out as soon as possible they need to know
the minimum number of buffers to queue before STREAMON can be called. You can't
just try STREAMON after every buffer since on failure STREAMON will dequeue
all your buffers. (Is that a bug or a feature? Frankly, I'm not sure).
This patch simplifies applications substantially: they can just call STREAMON
at the beginning and then start queuing buffers and the DMA engine will
kick in automagically once enough buffers are available.
This also fixes using write() to stream video: the fileio implementation
calls streamon without having any queued buffers, which will fail today for
any driver that requires a minimum number of buffers.
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Acked-by: Marek Szyprowski <m.szyprowski@samsung.com>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>
Rather than taking the mmap semaphore at a relatively high-level function,
push it down to the place where it is really needed.
It was placed in vb2_queue_or_prepare_buf() to prevent racing with other
vb2 calls. The only way I can see that a race can happen is when two
threads queue the same buffer. The solution for that it to introduce
a PREPARING state.
Moving it down offers opportunities to simplify the code.
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>
Currently it is not possible for userspace to map a DMABUF exported buffer
with write permissions. This patch allows to also pass O_RDONLY/O_RDWR when
exporting the buffer, so that userspace may map it with write permissions.
Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>
struct v4_file_operations defines the data param as
const char __user *data but on vb2 is defined as
char __user *data.
This patch fixes the warnings produced by this. ie:
drivers/qtec/qtec_xform.c:817:2: warning: initialization from
incompatible pointer type [enabled by default]
drivers/qtec/qtec_xform.c:817:2: warning: (near initialization for
‘qtec_xform_v4l_fops.write’) [enabled by default]
Signed-off-by: Ricardo Ribalda Delgado <ricardo.ribalda@gmail.com>
Acked-by: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>
Explain how the two operations must handle formats and validate buffer
sizes when used with VIDIOC_CREATE_BUFS.
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Acked-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>
Hans Verkuil