Commit Graph

87 Commits

Author SHA1 Message Date
Mauro Carvalho Chehab
60e7926b93 media: videobuf2-core: improve kernel-doc markups
Now that nested structs are supported, change the
documentation to use it. While here, add cross-references
where pertinent and use monotonic fonts where pertinent,
using the right markup tags.

Acked-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Acked-by: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2017-12-18 10:21:51 -05:00
Stanimir Varbanov
5b6f9abe5a media: vb2: add bidirectional flag in vb2_queue
This change is intended to give to the v4l2 drivers a choice to
change the default behavior of the v4l2-core DMA mapping direction
from DMA_TO/FROM_DEVICE (depending on the buffer type CAPTURE or
OUTPUT) to DMA_BIDIRECTIONAL during queue_init time.

Initially the issue with DMA mapping direction has been found in
Venus encoder driver where the hardware (firmware side) adds few
lines padding on bottom of the image buffer, and the consequence
is triggering of IOMMU protection faults.

This will help supporting venus encoder (and probably other drivers
in the future) which wants to map output type of buffers as
read/write.

Signed-off-by: Stanimir Varbanov <stanimir.varbanov@linaro.org>
Acked-by: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Hans Verkuil <hansverk@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2017-08-26 14:15:54 -04:00
Anton Leontiev
e5c27ef390 [media] vb2: Fix queue_setup() callback description
Correct meaning of the last sensence by swapping it with previous.
Fix two small typos.

Signed-off-by: Anton Leontiev <scileont@gmail.com>
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2017-04-05 15:11:07 -03:00
Mauro Carvalho Chehab
e383ce0736 [media] get rid of a number of problems at the cross references
As warned by linuxdoc[1] tool, using:

$ for i in $(git grep kernel-doc Documentation/media/kapi/|cut -d: -f4); do kernel-lintdoc --sloppy $i; done

    include/media/v4l2-dev.h:118 :WARN: function name from comment differs:  v4l2_prio_close <--> v4l2_prio_check
    include/media/v4l2-mc.h:56 [kernel-doc WARN] : enum name from comment differs:  if_vid_dec_index <--> if_vid_dec_pad_index
    include/media/v4l2-mc.h:71 [kernel-doc WARN] : enum name from comment differs:  if_aud_dec_index <--> if_aud_dec_pad_index
    include/media/v4l2-mem2mem.h:396 [kernel-doc WARN] : function name from comment differs:  v4l2_m2m_num_src_bufs_ready <--> v4l2_m2m_num_dst_bufs_ready
    drivers/media/dvb-core/dvb_math.h:28 [kernel-doc WARN] : function name from comment differs:  cintlog2 <--> intlog2
    include/media/v4l2-subdev.h:215 [kernel-doc WARN] : struct name from comment differs:  s_radio <--> v4l2_subdev_tuner_ops
    include/media/v4l2-subdev.h:890 [kernel-doc WARN] : function name from comment differs:  v4l2_set_subdevdata <--> v4l2_set_subdev_hostdata
    include/media/v4l2-subdev.h:901 [kernel-doc WARN] : function name from comment differs:  v4l2_get_subdevdata <--> v4l2_get_subdev_hostdata
    drivers/media/dvb-core/dvb_ringbuffer.h:196 [kernel-doc WARN] : function name from comment differs:  dvb_ringbuffer_writeuser <--> dvb_ringbuffer_write_user
    include/media/videobuf2-core.h:399 [kernel-doc WARN] : struct name from comment differs:  vb2_ops <--> vb2_buf_ops
    include/media/media-entity.h:132 [kernel-doc ERROR] : duplicate parameter definition 'source'
    include/media/media-entity.h:477 [kernel-doc WARN] : function name from comment differs:  media_entity_enum_test <--> media_entity_enum_test_and_set
    include/media/media-entity.h:535 [kernel-doc WARN] : function name from comment differs:  gobj_to_entity <--> gobj_to_pad
    include/media/media-entity.h:544 [kernel-doc WARN] : function name from comment differs:  gobj_to_entity <--> gobj_to_link
    include/media/media-entity.h:553 [kernel-doc WARN] : function name from comment differs:  gobj_to_entity <--> gobj_to_intf
    include/media/media-entity.h:562 [kernel-doc WARN] : function name from comment differs:  gobj_to_entity <--> intf_to_devnode
    include/media/rc-core.h:234 [kernel-doc WARN] : function name from comment differs:  rc_open <--> rc_close
    include/media/v4l2-ctrls.h:397 [kernel-doc WARN] : missing initial short description of 'v4l2_ctrl_handler_init'
    include/media/v4l2-dev.h:118 [kernel-doc WARN] : function name from comment differs:  v4l2_prio_close <--> v4l2_prio_check
    include/media/v4l2-event.h:225 [kernel-doc WARN] : missing initial short description of 'v4l2_src_change_event_subscribe'

[1] https://return42.github.io/linuxdoc/linux.html

The above are real issues at the documentation. On several cases,
caused by cut-and-paste.

 Fix them.

Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2016-09-22 10:00:23 -03:00
Mauro Carvalho Chehab
f286f4dfc5 [media] videobuf2-core.h: improve documentation
There are several small issues with the documentation. Fix them,
in order to avoid producing warnings.

While here, also make checkpatch.pl happy.

Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2016-09-09 10:17:39 -03:00
Mauro Carvalho Chehab
52839f66ed [media] videobuf2-core.h: document enum vb2_memory
This enum was not documented. Document it.

Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2016-09-09 10:16:53 -03:00
Mauro Carvalho Chehab
88b7eb092e [media] videobuf2-core.h: move function descriptions from c file
There are several functions that were documented at the .c
file. As we only include the headers, we need to move them to
there, in order to have documentation.

Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2016-09-09 10:14:50 -03:00
Hans Verkuil
0ff657b0f6 [media] vb2: don't return NULL for alloc and get_userptr ops
Always return an ERR_PTR() instead of NULL.

This makes the behavior of alloc, get_userptr and attach_dmabuf the
same.

Update the documentation in videobuf2-core.h as well.

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2016-08-24 10:10:40 -03:00
Krzysztof Kozlowski
00085f1efa dma-mapping: use unsigned long for dma_attrs
The dma-mapping core and the implementations do not change the DMA
attributes passed by pointer.  Thus the pointer can point to const data.
However the attributes do not have to be a bitfield.  Instead unsigned
long will do fine:

1. This is just simpler.  Both in terms of reading the code and setting
   attributes.  Instead of initializing local attributes on the stack
   and passing pointer to it to dma_set_attr(), just set the bits.

2. It brings safeness and checking for const correctness because the
   attributes are passed by value.

Semantic patches for this change (at least most of them):

    virtual patch
    virtual context

    @r@
    identifier f, attrs;

    @@
    f(...,
    - struct dma_attrs *attrs
    + unsigned long attrs
    , ...)
    {
    ...
    }

    @@
    identifier r.f;
    @@
    f(...,
    - NULL
    + 0
     )

and

    // Options: --all-includes
    virtual patch
    virtual context

    @r@
    identifier f, attrs;
    type t;

    @@
    t f(..., struct dma_attrs *attrs);

    @@
    identifier r.f;
    @@
    f(...,
    - NULL
    + 0
     )

Link: http://lkml.kernel.org/r/1468399300-5399-2-git-send-email-k.kozlowski@samsung.com
Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Acked-by: Vineet Gupta <vgupta@synopsys.com>
Acked-by: Robin Murphy <robin.murphy@arm.com>
Acked-by: Hans-Christian Noren Egtvedt <egtvedt@samfundet.no>
Acked-by: Mark Salter <msalter@redhat.com> [c6x]
Acked-by: Jesper Nilsson <jesper.nilsson@axis.com> [cris]
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch> [drm]
Reviewed-by: Bart Van Assche <bart.vanassche@sandisk.com>
Acked-by: Joerg Roedel <jroedel@suse.de> [iommu]
Acked-by: Fabien Dessenne <fabien.dessenne@st.com> [bdisp]
Reviewed-by: Marek Szyprowski <m.szyprowski@samsung.com> [vb2-core]
Acked-by: David Vrabel <david.vrabel@citrix.com> [xen]
Acked-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> [xen swiotlb]
Acked-by: Joerg Roedel <jroedel@suse.de> [iommu]
Acked-by: Richard Kuo <rkuo@codeaurora.org> [hexagon]
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org> [m68k]
Acked-by: Gerald Schaefer <gerald.schaefer@de.ibm.com> [s390]
Acked-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Acked-by: Hans-Christian Noren Egtvedt <egtvedt@samfundet.no> [avr32]
Acked-by: Vineet Gupta <vgupta@synopsys.com> [arc]
Acked-by: Robin Murphy <robin.murphy@arm.com> [arm64 and dma-iommu]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-08-04 08:50:07 -04:00
Mauro Carvalho Chehab
564aaf6920 [media] doc-rst: add some needed escape codes
Some extra escape codes are needed to avoid Sphinx to not
identify the tags.

Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2016-07-23 08:05:02 -03:00
Mauro Carvalho Chehab
c278256d05 Merge branch 'patchwork' into topic/docs-next
* patchwork: (1492 commits)
  [media] cec: always check all_device_types and features
  [media] cec: poll should check if there is room in the tx queue
  [media] vivid: support monitor all mode
  [media] cec: fix test for unconfigured adapter in main message loop
  [media] cec: limit the size of the transmit queue
  [media] cec: zero unused msg part after msg->len
  [media] cec: don't set fh to NULL in CEC_TRANSMIT
  [media] cec: clear all status fields before transmit and always fill in sequence
  [media] cec: CEC_RECEIVE overwrote the timeout field
  [media] cxd2841er: Reading SNR for DVB-C added
  [media] cxd2841er: Reading BER and UCB for DVB-C added
  [media] cxd2841er: fix switch-case for DVB-C
  [media] cxd2841er: fix signal strength scale for ISDB-T
  [media] cxd2841er: adjust the dB scale for DVB-C
  [media] cxd2841er: provide signal strength for DVB-C
  [media] cxd2841er: fix BER report via DVBv5 stats API
  [media] mb86a20s: apply mask to val after checking for read failure
  [media] airspy: fix error logic during device register
  [media] s5p-cec/TODO: add TODO item
  [media] cec/TODO: drop comment about sphinx documentation
  ...

Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2016-07-23 07:59:19 -03:00
Mauro Carvalho Chehab
89cb3ddbe7 [media] doc-rst: Fix conversion for v4l2 core functions
The conversion from DocBook lead into some conversion issues,
basically due to the lack of proper support at kernel-doc.

So, address them:

- Now, the C files with the exported symbols also need to be
  added. So, all headers need to be included twice: one to
  get the structs/enums/.. and another one for the functions;

- Notes should use the ReST tag, as kernel-doc doesn't
  recognizes it anymore;

- Identation needs to be fixed, as ReST uses it to identify
  when a format "tag" ends.

- kernel-doc doesn't escape things like *pointer, so we
  need to manually add a escape char before it.

- On some cases, kernel-doc conversion requires violating
  the 80-cols, as otherwise it won't properly parse the
  source code.

Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2016-07-17 14:02:43 -03:00
Hans Verkuil
36c0f8b32c [media] vb2: replace void *alloc_ctxs by struct device *alloc_devs
Make this a proper typed array. Drop the old allocate context code since
that is no longer used.

Note that the memops functions now get a struct device pointer instead of
the struct device ** that was there initially (actually a void pointer to
a struct containing only a struct device pointer).

This code is now a lot cleaner.

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Cc: Sakari Ailus <sakari.ailus@iki.fi>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2016-07-08 14:45:07 -03:00
Hans Verkuil
20be7ab8db [media] vb2: add a dev field to use for the default allocation context
The allocation context is nothing more than a per-plane device pointer
to use when allocating buffers. So just provide a dev pointer in vb2_queue
for that purpose and drivers can skip allocating/releasing/filling in
the allocation context unless they require different per-plane device
pointers as used by some Samsung SoCs.

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Cc: Sakari Ailus <sakari.ailus@iki.fi>
Cc: Florian Echtler <floe@butterbrot.org>
Cc: Federico Vaga <federico.vaga@gmail.com>
Cc: "Lad, Prabhakar" <prabhakar.csengg@gmail.com>
Cc: Scott Jiang <scott.jiang.linux@gmail.com>
Acked-by: Philipp Zabel <p.zabel@pengutronix.de>
Cc: Fabien Dessenne <fabien.dessenne@st.com>
Acked-by: Benoit Parrot <bparrot@ti.com>
Cc: Mikhail Ulyanov <mikhail.ulyanov@cogentembedded.com>
Cc: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Ludovic Desroches <ludovic.desroches@atmel.com>
Cc: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
Cc: Kyungmin Park <kyungmin.park@samsung.com>
Cc: Sylwester Nawrocki <s.nawrocki@samsung.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2016-07-08 14:34:16 -03:00
Hans Verkuil
d16e832da2 [media] vb2: move dma_attrs to vb2_queue
Make the dma attributes struct part of vb2_queue. This greatly simplifies
the remainder of the patch series since the dma_contig alloc context is
now (as before) just a struct device pointer.

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Cc: Sakari Ailus <sakari.ailus@iki.fi>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2016-07-08 14:30:50 -03:00
Ricardo Ribalda
b93876845c [media] media: vb2: Fix regression on poll() for RW mode
When using a device is read/write mode, vb2 does not handle properly the
first select/poll operation.

The reason for this, is that when this code has been refactored, some of
the operations have changed their order, and now fileio emulator is not
started.

The reintroduced check to the core is enabled by a quirk flag, that
avoids this check by other subsystems like DVB.

Fixes: 49d8ab9fea ("media] media: videobuf2: Separate vb2_poll()")

Reported-by: Dimitrios Katsaros <patcherwork@gmail.com>
Cc: Junghak Sung <jh1009.sung@samsung.com>
Cc: <stable@vger.kernel.org>      # for v4.5 and up
Signed-off-by: Ricardo Ribalda Delgado <ricardo.ribalda@gmail.com>
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
2016-04-25 10:21:23 -03:00
Sakari Ailus
e7e0c3e265 [media] videobuf2-core: Check user space planes array in dqbuf
The number of planes in videobuf2 is specific to a buffer. In order to
verify that the planes array provided by the user is long enough, a new
vb2_buf_op is required.

Call __verify_planes_array() when the dequeued buffer is known. Return an
error to the caller if there was one, otherwise remove the buffer from the
done list.

Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Acked-by: Hans Verkuil <hans.verkuil@cisco.com>
Cc: stable@vger.kernel.org # for v4.4 and later
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
2016-04-13 16:19:05 -03:00
Hans Verkuil
fac710e45d [media] vb2: fix nasty vb2_thread regression
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>
2016-02-04 09:13:46 -02:00
Hans Verkuil
58e1ba3ce6 [media] videobuf2-core: fix plane_sizes handling in VIDIOC_CREATE_BUFS
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>
2015-12-18 14:05:58 -02:00
Hans Verkuil
10cc3b1e12 [media] videobuf2-core: fill_user_buffer and copy_timestamp should return void
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>
2015-12-18 14:00:50 -02:00
Junghak Sung
af3bac1a7c [media] media: videobuf2: Move vb2_fileio_data and vb2_thread to core part
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>
2015-12-18 13:58:09 -02:00
Junghak Sung
959c3ef336 [media] media: videobuf2: Add copy_timestamp to struct vb2_queue
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>
2015-12-18 13:54:33 -02:00
Junghak Sung
d6dd645eae [media] media: videobuf2: Move timestamp to vb2_buffer
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>
2015-12-18 13:53:31 -02:00
Hans Verkuil
df9ecb0cad [media] vb2: drop v4l2_format argument from queue_setup
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>
2015-12-18 13:48:19 -02:00
Junghak Sung
3c5be988e0 [media] media: videobuf2: Move v4l2-specific stuff to videobuf2-v4l2
Move v4l2-specific stuff from videobu2-core to videobuf2-v4l2
without doing any functional changes.

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>
2015-10-20 15:14:28 -02:00
Junghak Sung
b0e0e1f83d [media] media: videobuf2: Prepare to divide videobuf2
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>
2015-10-20 15:12:45 -02:00
Junghak Sung
bed04f9342 [media] media: videobuf2: Replace v4l2-specific data with vb2 data
Simple changes that replace v4l2-specific data with vb2 data
in videobuf2-core.

enum v4l2_buf_type --> int
enum v4l2_memory --> enum vb2_memory
VIDEO_MAX_FRAME --> VB2_MAX_FRAME
VIDEO_MAX_PLANES --> VB2_MAX_PLANES
struct v4l2_fh *owner --> void *owner
V4L2_TYPE_IS_MULTIPLANAR() --> is_multiplanar
V4L2_TYPE_IS_OUTPUT() --> is_output

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>
2015-10-20 14:49:39 -02:00
Junghak Sung
33119e80c3 [media] media: videobuf2: Change queue_setup argument
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>
2015-10-20 14:48:39 -02:00
Mauro Carvalho Chehab
efe98010b8 [media] DocBook: Fix remaining issues with VB2 core documentation
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>
2015-10-05 09:12:56 -03:00
Mauro Carvalho Chehab
32d81b41cd [media] DocBook: fix most of warnings at videobuf2-core.h
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>
2015-10-01 13:59:29 -03:00
Junghak Sung
2d7007153f [media] media: videobuf2: Restructure vb2_buffer
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>
2015-10-01 09:04:43 -03:00
Junghak Sung
c139990e84 [media] media: videobuf2: Replace videobuf2-core with videobuf2-v4l2
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>
2015-10-01 08:48:18 -03:00
Linus Torvalds
9cfcc658da media updates for v4.3-rc1
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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
  ...
2015-09-05 18:21:14 -07:00
Mauro Carvalho Chehab
d78757e780 [media] videobuf2-core: Add it to device-drivers DocBook
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>
2015-08-22 09:05:54 -03:00
Sakari Ailus
6d058c5643 [media] vb2: Only requeue buffers immediately once streaming is started
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>
2015-07-17 09:00:12 -03:00
Philipp Zabel
c16218402a [media] videobuf2: return -EPIPE from DQBUF after the last buffer
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>
2015-05-12 03:53:06 -03:00
Kamil Debski
f61bf13b6a [media] vb2: add allow_zero_bytesused flag to the vb2_queue struct
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>
2015-04-10 09:46:07 -03:00
Kamil Debski
06e7a9b638 [media] vb2: split the io_flags member of vb2_queue into a bit field
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>
2015-04-10 09:44:38 -03:00
Hans Verkuil
d935c57e8f [media] vb2: add dma_dir to the alloc memop
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>
2014-11-25 08:51:44 -02:00
Hans Verkuil
cd474037c4 [media] vb2: replace 'write' by 'dma_dir'
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>
2014-11-25 08:50:28 -02:00
Hans Verkuil
cf227429c7 [media] videobuf2-core.h: improve documentation
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>
2014-11-25 08:47:24 -02:00
Mauro Carvalho Chehab
a66d05d504 Merge branch 'patchwork' into v4l_for_linus
* patchwork: (544 commits)
  [media] ir-hix5hd2: fix build on c6x arch
  [media] pt3: fix DTV FE I2C driver load error paths
  Revert "[media] media: em28xx - remove reset_resume interface"
  [media] exynos4-is: fix some warnings when compiling on arm64
  [media] usb drivers: use %zu instead of %zd
  [media] pci drivers: use %zu instead of %zd
  [media] dvb-frontends: use %zu instead of %zd
  [media] s5p-mfc: Fix several printk warnings
  [media] s5p_mfc_opr: Fix warnings
  [media] ti-vpe: Fix typecast
  [media] s3c-camif: fix dma_addr_t printks
  [media] s5p_mfc_opr_v6: get rid of warnings when compiled with 64 bits
  [media] s5p_mfc_opr_v5: Fix lots of warnings on x86_64
  [media] em28xx: Fix identation
  [media] drxd: remove a dead code
  [media] saa7146: remove return after BUG()
  [media] cx88: remove return after BUG()
  [media] cx88: fix cards table CodingStyle
  [media] radio-sf16fmr2: declare some structs as static
  [media] radio-sf16fmi: declare pnp_attached as static
  ...

Conflicts:
	Documentation/DocBook/media/v4l/compat.xml
2014-10-09 14:00:54 -03:00
Laurent Pinchart
072f1a489e [media] v4l: videobuf2: Fix typos in comments
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>
2014-09-23 16:13:40 -03:00
Hans Verkuil
58d75f4b1c [media] vb2: fix VBI/poll regression
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>
2014-09-21 20:57:30 -03:00
Hans Verkuil
44e8e69d46 [media] videobuf2-core.h: fix comment
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>
2014-09-21 20:45:23 -03:00
Prabhakar Lad
ead130335f [media] media: videobuf2-core.h: add a helper to get status of start_streaming()
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>
2014-09-21 20:15:39 -03:00
Hans Verkuil
f035eb4e97 [media] videobuf2: fix lockdep warning
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>
2014-08-21 15:25:31 -05:00
Hans Verkuil
ccf58cb4ea [media] vb2: fix videobuf2-core.h comments
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>
2014-07-25 19:19:35 -03:00
Laurent Pinchart
4bb7267dc4 [media] v4l: vb2: Add fatal error condition flag
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>
2014-07-17 16:19:04 -03:00
Laurent Pinchart
34ea4d4417 [media] v4l: vb2: Add a function to discard all DONE buffers
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>
2014-05-25 11:37:49 -03:00