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author | Linus Torvalds <torvalds@linux-foundation.org> | 2016-07-27 21:58:31 (GMT) |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2016-07-27 21:58:31 (GMT) |
commit | ff9a082fda424257976f08fce942609f358015e0 (patch) | |
tree | 478e6b449b19baaf842369a13923499ce83ef895 /Documentation/media/uapi/gen-errors.rst | |
parent | 6a492b0f23d28e1f946cdf08e54617484400dafb (diff) | |
parent | 85538b1ad145c67198cb55d02de14ba269cc323d (diff) | |
download | linux-ff9a082fda424257976f08fce942609f358015e0.tar.xz |
Merge tag 'media/v4.8-4' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media
Pull media documentation updates from Mauro Carvalho Chehab:
"This patch series does the conversion of all media documentation stuff
to Restrutured Text markup format and add them to the
Documentation/index.rst file.
The media documentation was grouped into 4 books:
- media uAPI
- media kAPI
- V4L driver-specific documentation
- DVB driver-specific documentation
It also contains several documentation improvements and one fixup
patch for a core issue with cropcap.
PS. After this patch series, the media DocBook is deprecated and
should be removed. I'll add such patch on a future pull request"
* tag 'media/v4.8-4' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media: (322 commits)
[media] cx23885-cardlist.rst: add a new card
[media] doc-rst: add some needed escape codes
[media] doc-rst: kapi: use :c:func: instead of :cpp:func
doc-rst: kernel-doc: fix a change introduced by mistake
[media] v4l2-ioctl.h add debug info for struct v4l2_ioctl_ops
[media] dvb_ringbuffer.h: some documentation improvements
[media] v4l2-ctrls.h: fully document the header file
[media] doc-rst: Fix some typedef ugly warnings
[media] doc-rst: reorganize the kAPI v4l2 chapters
[media] rename v4l2-framework.rst to v4l2-intro.rst
[media] move V4L2 clocks to a separate .rst file
[media] v4l2-fh.rst: add cross references and markups
[media] v4l2-fh.rst: add fh contents from v4l2-framework.rst
[media] v4l2-fh.h: add documentation for it
[media] v4l2-event.rst: add cross-references and markups
[media] v4l2-event.h: document all functions
[media] v4l2-event.rst: add text from v4l2-framework.rst
[media] v4l2-framework.rst: remove videobuf quick chapter
[media] v4l2-dev: add cross-references and improve markup
[media] doc-rst: move v4l2-dev doc to a separate file
...
Diffstat (limited to 'Documentation/media/uapi/gen-errors.rst')
-rw-r--r-- | Documentation/media/uapi/gen-errors.rst | 103 |
1 files changed, 103 insertions, 0 deletions
diff --git a/Documentation/media/uapi/gen-errors.rst b/Documentation/media/uapi/gen-errors.rst new file mode 100644 index 0000000..d6b0cfd --- /dev/null +++ b/Documentation/media/uapi/gen-errors.rst @@ -0,0 +1,103 @@ +.. -*- coding: utf-8; mode: rst -*- + +.. _gen_errors: + +******************* +Generic Error Codes +******************* + + +.. _gen-errors: + +.. flat-table:: Generic error codes + :header-rows: 0 + :stub-columns: 0 + :widths: 1 16 + + + - .. row 1 + + - ``EAGAIN`` (aka ``EWOULDBLOCK``) + + - The ioctl can't be handled because the device is in state where it + can't perform it. This could happen for example in case where + device is sleeping and ioctl is performed to query statistics. It + is also returned when the ioctl would need to wait for an event, + but the device was opened in non-blocking mode. + + - .. row 2 + + - ``EBADF`` + + - The file descriptor is not a valid. + + - .. row 3 + + - ``EBUSY`` + + - The ioctl can't be handled because the device is busy. This is + typically return while device is streaming, and an ioctl tried to + change something that would affect the stream, or would require + the usage of a hardware resource that was already allocated. The + ioctl must not be retried without performing another action to fix + the problem first (typically: stop the stream before retrying). + + - .. row 4 + + - ``EFAULT`` + + - There was a failure while copying data from/to userspace, probably + caused by an invalid pointer reference. + + - .. row 5 + + - ``EINVAL`` + + - One or more of the ioctl parameters are invalid or out of the + allowed range. This is a widely used error code. See the + individual ioctl requests for specific causes. + + - .. row 6 + + - ``ENODEV`` + + - Device not found or was removed. + + - .. row 7 + + - ``ENOMEM`` + + - There's not enough memory to handle the desired operation. + + - .. row 8 + + - ``ENOTTY`` + + - The ioctl is not supported by the driver, actually meaning that + the required functionality is not available, or the file + descriptor is not for a media device. + + - .. row 9 + + - ``ENOSPC`` + + - On USB devices, the stream ioctl's can return this error, meaning + that this request would overcommit the usb bandwidth reserved for + periodic transfers (up to 80% of the USB bandwidth). + + - .. row 10 + + - ``EPERM`` + + - Permission denied. Can be returned if the device needs write + permission, or some special capabilities is needed (e. g. root) + +.. note:: + + #. This list is not exaustive; ioctls may return other error codes. + Since errors may have side effects such as a driver reset, + applications should abort on unexpected errors, or otherwise + assume that the device is in a bad state. + + #. Request-specific error codes are listed in the individual + requests descriptions. |