From d0b2f91bede3bd5e3d24dd6803e56eee959c1797 Mon Sep 17 00:00:00 2001 From: André Fabian Silva Delgado Date: Thu, 20 Oct 2016 00:10:27 -0300 Subject: Linux-libre 4.8.2-gnu --- Documentation/media/uapi/gen-errors.rst | 103 ++++++++++++++++++++++++++++++++ 1 file changed, 103 insertions(+) create mode 100644 Documentation/media/uapi/gen-errors.rst (limited to 'Documentation/media/uapi/gen-errors.rst') diff --git a/Documentation/media/uapi/gen-errors.rst b/Documentation/media/uapi/gen-errors.rst new file mode 100644 index 000000000..d6b0cfd00 --- /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. -- cgit v1.2.3-54-g00ecf