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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-27 10:05:51 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-27 10:05:51 +0000 |
commit | 5d1646d90e1f2cceb9f0828f4b28318cd0ec7744 (patch) | |
tree | a94efe259b9009378be6d90eb30d2b019d95c194 /Documentation/userspace-api/media/gen-errors.rst | |
parent | Initial commit. (diff) | |
download | linux-430c2fc249ea5c0536abd21c23382884005c9093.tar.xz linux-430c2fc249ea5c0536abd21c23382884005c9093.zip |
Adding upstream version 5.10.209.upstream/5.10.209upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'Documentation/userspace-api/media/gen-errors.rst')
-rw-r--r-- | Documentation/userspace-api/media/gen-errors.rst | 96 |
1 files changed, 96 insertions, 0 deletions
diff --git a/Documentation/userspace-api/media/gen-errors.rst b/Documentation/userspace-api/media/gen-errors.rst new file mode 100644 index 000000000..e595d0bea --- /dev/null +++ b/Documentation/userspace-api/media/gen-errors.rst @@ -0,0 +1,96 @@ +.. SPDX-License-Identifier: GFDL-1.1-no-invariants-or-later + +.. _gen_errors: + +******************* +Generic Error Codes +******************* + + +.. _gen-errors: + +.. tabularcolumns:: |p{2.5cm}|p{15.0cm}| + +.. flat-table:: Generic error codes + :header-rows: 0 + :stub-columns: 0 + :widths: 1 16 + + + - - ``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. + + - - ``EBADF`` + + - The file descriptor is not a valid. + + - - ``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). + + - - ``EFAULT`` + + - There was a failure while copying data from/to userspace, probably + caused by an invalid pointer reference. + + - - ``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. + + - - ``ENODEV`` + + - Device not found or was removed. + + - - ``ENOMEM`` + + - There's not enough memory to handle the desired operation. + + - - ``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. + + - - ``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). + + - - ``EPERM`` + + - Permission denied. Can be returned if the device needs write + permission, or some special capabilities is needed (e. g. root) + + - - ``EIO`` + + - I/O error. Typically used when there are problems communicating with + a hardware device. This could indicate broken or flaky hardware. + It's a 'Something is wrong, I give up!' type of error. + + - - ``ENXIO`` + + - No device corresponding to this device special file exists. + + +.. note:: + + #. This list is not exhaustive; 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. |