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-rw-r--r-- | Documentation/video4linux/v4l2-framework.txt | 11 |
1 files changed, 5 insertions, 6 deletions
diff --git a/Documentation/video4linux/v4l2-framework.txt b/Documentation/video4linux/v4l2-framework.txt index 5155700c206b..5b9205a17ae7 100644 --- a/Documentation/video4linux/v4l2-framework.txt +++ b/Documentation/video4linux/v4l2-framework.txt | |||
@@ -545,12 +545,11 @@ unregister them: | |||
545 | This will remove the device nodes from sysfs (causing udev to remove them | 545 | This will remove the device nodes from sysfs (causing udev to remove them |
546 | from /dev). | 546 | from /dev). |
547 | 547 | ||
548 | After video_unregister_device() returns no new opens can be done. | 548 | After video_unregister_device() returns no new opens can be done. However, |
549 | 549 | in the case of USB devices some application might still have one of these | |
550 | However, in the case of USB devices some application might still have one | 550 | device nodes open. So after the unregister all file operations will return |
551 | of these device nodes open. You should block all new accesses to read, | 551 | an error as well, except for the ioctl and unlocked_ioctl file operations: |
552 | write, poll, etc. except possibly for certain ioctl operations like | 552 | those will still be passed on since some buffer ioctls may still be needed. |
553 | queueing buffers. | ||
554 | 553 | ||
555 | When the last user of the video device node exits, then the vdev->release() | 554 | When the last user of the video device node exits, then the vdev->release() |
556 | callback is called and you can do the final cleanup there. | 555 | callback is called and you can do the final cleanup there. |