There are multiple places where arrays or otherwise variable sized
buffer are allocated through V4L2 core code, including things like
controls, memory pages, staging buffers for ioctls and so on. Such
allocations can potentially require an order > 0 allocation from the
page allocator, which is not guaranteed to be fulfilled and is likely to
fail on a system with severe memory fragmentation (e.g. a system with
very long uptime).
Since the memory being allocated is intended to be used by the CPU
exclusively, we can consider using vmalloc() as a fallback and this is
exactly what the recently merged kvmalloc() helpers do. A kmalloc() call
is still attempted, even for order > 0 allocations, but it is done
with __GFP_NORETRY and __GFP_NOWARN, with expectation of failing if
requested memory is not available instantly. Only then the vmalloc()
fallback is used. This should give us fast and more reliable allocations
even on systems with higher memory pressure and/or more fragmentation,
while still retaining the same performance level on systems not
suffering from such conditions.
While at it, replace explicit array size calculations on changed
allocations with kvmalloc_array().
Purposedly not touching videobuf1, as it is deprecated, has only few
users remaining and would rather be seen removed instead.
Signed-off-by: Tomasz Figa <tfiga@chromium.org>
Acked-by: Marek Szyprowski <m.szyprowski@samsung.com>
Acked-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
Drop the FSF's postal address from the source code files that typically
contain mostly the license text. Of the 628 removed instances, 578 are
outdated.
The patch has been created with the following command without manual edits:
git grep -l "675 Mass Ave\|59 Temple Place\|51 Franklin St" -- \
drivers/media/ include/media|while read i; do i=$i perl -e '
open(F,"< $ENV{i}");
$a=join("", <F>);
$a =~ s/[ \t]*\*\n.*You should.*\n.*along with.*\n.*(\n.*USA.*$)?\n//m
&& $a =~ s/(^.*)Or, (point your browser to) /$1To obtain the license, $2\n$1/m;
close(F);
open(F, "> $ENV{i}");
print F $a;
close(F);'; done
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
If the vdev pointer == NULL, then just return.
This makes it easier for subdev drivers to use this function without having to
check if the sd->devnode pointer is NULL or not.
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Acked-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
This event indicates that the video device has encountered
a source parameter change during runtime. This can typically be a
resolution change detected by a video decoder OR a format change
detected by an input connector.
This needs to be nofified to the userspace and the application may
be expected to reallocate buffers before proceeding. The application
can subscribe to events on a specific pad or input port which
it is interested in.
Signed-off-by: Arun Kumar K <arun.kk@samsung.com>
Acked-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>
Add a v4l2 core helper function that can be used as the subdev
.unsubscribe_event handler. This allows to eliminate some
boilerplate from drivers that are only handling the control events.
Signed-off-by: Sylwester Nawrocki <sylvester.nawrocki@gmail.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Update contact information to correspond my e-mail address changes.
Signed-off-by: Sakari Ailus <sakari.ailus@iki.fi>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Write-only ioctls should have a const argument in the ioctl op.
Do this conversion for vidioc_(un)subscribe_event.
Adding const for write-only ioctls was decided during the 2012 Media Workshop.
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Currently, the v4l2 core is mixed together with other non-core drivers.
Move them into a separate directory.
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
