diff --git a/Documentation/DocBook/media/v4l/vidioc-enum-fmt.xml b/Documentation/DocBook/media/v4l/vidioc-enum-fmt.xml index 81ebe48317fe..0bd332421407 100644 --- a/Documentation/DocBook/media/v4l/vidioc-enum-fmt.xml +++ b/Documentation/DocBook/media/v4l/vidioc-enum-fmt.xml @@ -58,6 +58,9 @@ structure. Drivers fill the rest of the structure or return an incrementing by one until EINVAL is returned. + Note that after switching input or output the list of enumerated image +formats may be different. + struct <structname>v4l2_fmtdesc</structname> diff --git a/Documentation/DocBook/media/v4l/vidioc-g-fmt.xml b/Documentation/DocBook/media/v4l/vidioc-g-fmt.xml index 52acff193a6f..b4b0e0a28545 100644 --- a/Documentation/DocBook/media/v4l/vidioc-g-fmt.xml +++ b/Documentation/DocBook/media/v4l/vidioc-g-fmt.xml @@ -81,7 +81,7 @@ the application calls the VIDIOC_S_FMT ioctl with a pointer to a v4l2_format structure the driver checks and adjusts the parameters against hardware abilities. Drivers -should not return an error code unless the input is ambiguous, this is +should not return an error code unless the type field is invalid, this is a mechanism to fathom device capabilities and to approach parameters acceptable for both the application and driver. On success the driver may program the hardware, allocate resources and generally prepare for @@ -107,6 +107,10 @@ disabling I/O or possibly time consuming hardware preparations. Although strongly recommended drivers are not required to implement this ioctl. + The format as returned by VIDIOC_TRY_FMT +must be identical to what VIDIOC_S_FMT returns for +the same input or output. +
struct <structname>v4l2_format</structname> @@ -187,8 +191,7 @@ capture and output devices. EINVAL The &v4l2-format; type -field is invalid, the requested buffer type not supported, or the -format is not supported with this buffer type. +field is invalid or the requested buffer type not supported.