projects / deliverable / linux.git / blame
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|---|---|---|
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1 | .. -*- coding: utf-8; mode: rst -*- |
| 2 | ||
| af4a4d0d | 3 | .. _VIDIOC_LOG_STATUS: |
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4 | |
| 5 | *********************** | |
| 6 | ioctl VIDIOC_LOG_STATUS | |
| 7 | *********************** | |
| 8 | ||
| 15e7d615 | 9 | Name |
| 586027ce | 10 | ==== |
| 5377d91f | 11 | |
| 586027ce | 12 | VIDIOC_LOG_STATUS - Log driver status information |
| 5377d91f | 13 | |
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14 | |
| 15 | Synopsis | |
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16 | ======== |
| 17 | ||
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18 | .. c:function:: int ioctl( int fd, VIDIOC_LOG_STATUS) |
| 19 | :name: VIDIOC_LOG_STATUS | |
| 5377d91f | 20 | |
| 586027ce | 21 | |
| 15e7d615 | 22 | Arguments |
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23 | ========= |
| 24 | ||
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25 | ``fd`` |
| 26 | File descriptor returned by :ref:`open() <func-open>`. | |
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27 | |
| 28 | ||
| 15e7d615 | 29 | Description |
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30 | =========== |
| 31 | ||
| 32 | As the video/audio devices become more complicated it becomes harder to | |
| 33 | debug problems. When this ioctl is called the driver will output the | |
| 34 | current device status to the kernel log. This is particular useful when | |
| 35 | dealing with problems like no sound, no video and incorrectly tuned | |
| 36 | channels. Also many modern devices autodetect video and audio standards | |
| 37 | and this ioctl will report what the device thinks what the standard is. | |
| 38 | Mismatches may give an indication where the problem is. | |
| 39 | ||
| 40 | This ioctl is optional and not all drivers support it. It was introduced | |
| 41 | in Linux 2.6.15. | |
| 42 | ||
| 43 | ||
| 15e7d615 | 44 | Return Value |
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45 | ============ |
| 46 | ||
| 47 | On success 0 is returned, on error -1 and the ``errno`` variable is set | |
| 48 | appropriately. The generic error codes are described at the | |
| 49 | :ref:`Generic Error Codes <gen-errors>` chapter. |