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>
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>
Some drivers have special memory requirements for their buffers, usually
related to DMA (e.g. GFP_DMA or __GFP_DMA32). Make it possible to specify
additional GFP flags for those buffers by adding a gfp_flags field to
vb2_queue.
Note that this field will be replaced in the future with a different
mechanism, but that is still work in progress and we need this feature
now so we won't be able to convert drivers with such requirements to vb2.
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Acked-by: Marek Szyprowski <m.szyprowski@samsung.com>
Acked-by: Federico Vaga <federico.vaga@gmail.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Not all drivers use monotonic timestamps. This patch adds a way to set the
timestamp type per every queue.
In addition, set proper timestamp type in drivers that I am sure that use
either MONOTONIC or COPY timestamps. Other drivers will correctly report
UNKNOWN timestamp type instead of assuming that all drivers use monotonic
timestamps.
Signed-off-by: Kamil Debski <k.debski@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Reviewed-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
Acked-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
This patch adds extension to videobuf2-core. It allow to export an mmap buffer
as a DMABUF file descriptor.
Signed-off-by: Tomasz Stanislawski <t.stanislaws@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Acked-by: Hans Verkuil <hans.verkuil@cisco.com>
Tested-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
This patch adds support for prepare/finish callbacks in VB2 allocators. These
callback are used for buffer flushing.
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Acked-by: Hans Verkuil <hans.verkuil@cisco.com>
Tested-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
This patch adds support for DMABUF memory type in videobuf2. It calls relevant
APIs of dma_buf for v4l reqbuf / qbuf / dqbuf operations.
For this version, the support is for videobuf2 as a user of the shared buffer;
so the allocation of the buffer is done outside of V4L2. [A sample allocator of
dma-buf shared buffer is given at [1]]
[1]: Rob Clark's DRM:
https://github.com/robclark/kernel-omap4/commits/drmplane-dmabuf
[original work in the PoC for buffer sharing]
Signed-off-by: Tomasz Stanislawski <t.stanislaws@samsung.com>
Signed-off-by: Sumit Semwal <sumit.semwal@ti.com>
Signed-off-by: Sumit Semwal <sumit.semwal@linaro.org>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Acked-by: Hans Verkuil <hans.verkuil@cisco.com>
Tested-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
This replaces BUG_ON() calls with WARN_ON(), and returns
EINVAL if some parameter is NULL, as suggested by Jonathan and Mauro.
The BUG_ON() call is too drastic to be used in this case.
See the full discussion here:
http://www.spinics.net/lists/linux-media/msg52462.html
Signed-off-by: Ezequiel Garcia <elezegarcia@gmail.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Add helper functions to make it easier to adapt drivers to vb2.
These helpers take care of core locking and check if the filehandle is the
owner of the queue.
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
This prepares struct video_device for easier integration with vb2.
It also introduces a new lock that protects the vb2_queue. It is up
to the driver to use it or not. And the driver can associate an owner
filehandle with the queue to check whether queuing requests are
permitted for the calling filehandle.
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
no mmu system needs get_unmapped_area file operations to do mmap
Signed-off-by: Scott Jiang <scott.jiang.linux@gmail.com>
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
The two recently added ioctl()s VIDIOC_CREATE_BUFS and VIDIOC_PREPARE_BUF
allow user-space applications to allocate video buffers of different
sizes and hand them over to the driver for fast switching between
different frame formats. This patch adds support for buffers of different
sizes on the same buffer-queue to vb2.
Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
In preparation for the forthcoming VIDIOC_CREATE_BUFS ioctl add a
"const struct v4l2_format *" argument to the .queue_setup() vb2
operation.
Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
This patch prepares for a better separation of the buffer preparation
stage.
Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
This patch changes the order of operations during stream on call. Now the
buffers are first queued to the driver and then the start_streaming method
is called.
This resolves the most common case when the driver needs to know buffer
addresses to enable dma engine and start streaming. Additional parameter
to start_streaming method have been added to simplify drivers code. The
driver are now obliged to check if the number of queued buffers is high
enough to enable hardware streaming. If not - it can return an error. In
such case all the buffers that have been pre-queued are invalidated.
This patch also updates all videobuf2 clients to work properly with the
changed order of operations.
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
CC: Pawel Osciak <pawel@osciak.com>
CC: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
CC: Hans Verkuil <hverkuil@xs4all.nl>
CC: Tomasz Stanislawski <t.stanislaws@samsung.com>
CC: Sylwester Nawrocki <s.nawrocki@samsung.com>
CC: Kamil Debski <k.debski@samsung.com>
CC: Jonathan Corbet <corbet@lwn.net>
CC: Josh Wu <josh.wu@atmel.com>
CC: Hans de Goede <hdegoede@redhat.com>
CC: Paul Mundt <lethal@linux-sh.org>
Tested-by: Josh Wu <josh.wu@atmel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Plane sizes array was declared as unsigned long[], while unsigned int is
more than enough for storing size of the video buffer. This patch reduces
the size of the array by definiting it as unsigned int[].
Reported-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
CC: Pawel Osciak <pawel@osciak.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
MAPPED flag was set for the buffer only if all it's planes were mapped and
relied on a simple mapping counter. This assumption is really bogus,
especially because the buffers may be mapped multiple times. Also the
meaning of this flag for muliplane buffers was not really useful. This
patch fixes this issue by setting the MAPPED flag for the buffer if any of
it's planes is in use (what means that has been mapped at least once), so
MAPPED flag can be used as 'in_use' indicator.
Reported-by: Hans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
CC: Pawel Osciak <pawel@osciak.com>
Tested-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Videobuf2 accepted any userptr buffer without verifying if its size is
large enough to store the video data from the driver. The driver reports
the minimal size of video data once in queue_setup and expects that
videobuf2 provides buffers that match these requirements. This patch
adds the required check.
Reported-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
CC: Pawel Osciak <pawel@osciak.com>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
vb2_get_plane_payload() gets the bytesused field for a plane, it doesn't
set it.
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Add a generic file io (read and write) emulator for videobuf2. It uses
MMAP memory type buffers and generic vb2 calls: req_bufs, qbuf and
dqbuf. Video date is being copied from mmap buffers to userspace with
standard copy_to_user() function. To add support for file io the driver
needs to provide an additional callback - read_setup or write_setup. It
should provide the default number of buffers used by emulator and flags.
With these flags one can detemine the style of read() or write()
emulation. By default 'streaming' style is used. With
VB2_FILEIO_READ_ONCE flag one can select 'one shot' mode for read()
emulator. With VB2_FILEIO_WRITE_IMMEDIATE flag one can select immediate
conversion of write calls to qbuf for write() emulator, so the vb2 will
not wait until each buffer is filled completely before queueing it to
the driver.
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
CC: Pawel Osciak <pawel@osciak.com>
Reviewed-by: Hans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Videobuf2 is a Video for Linux 2 API-compatible driver framework for
multimedia devices. It acts as an intermediate layer between userspace
applications and device drivers. It also provides low-level, modular
memory management functions for drivers.
Videobuf2 eases driver development, reduces drivers' code size and aids in
proper and consistent implementation of V4L2 API in drivers.
Videobuf2 memory management backend is fully modular. This allows custom
memory management routines for devices and platforms with non-standard
memory management requirements to be plugged in, without changing the
high-level buffer management functions and API.
The framework provides:
- implementations of streaming I/O V4L2 ioctls and file operations
- high-level video buffer, video queue and state management functions
- video buffer memory allocation and management
Signed-off-by: Pawel Osciak <p.osciak@samsung.com>
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
CC: Pawel Osciak <pawel@osciak.com>
Reviewed-by: Hans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Hans Verkuil
Hans Verkuil
Laurent Pinchart
Sakari Ailus
Ricardo Ribalda
Philipp Zabel
Laurent Pinchart
Kamil Debski
Tomasz Stanislawski
Marek Szyprowski
Sumit Semwal
Ezequiel Garcia
Scott Jiang
Guennadi Liakhovetski
Pawel Osciak
Pawel Osciak