A new device driver for a video frame grbber一个视频帧捕获一个新的设备驱动程序.pptVIP

A new device driver for a video frame grabber Binh Tran – Lucie Ngnepieba Outline Overview Our goals Our achievement 4. Difficulties and our solutions 5. Discovered facts and our learns 6. Future works 7. Conclusion Overview Goals To compile correctly on the Linux distribution 2.6.16 To improve the previous Video frame grabber device driver to support Video4Linux. To integrate the previous driver and make it work on both grayscale and color support. To work on the low-level operation of the frame grabber to support the new interrupt-driven I/O feature (if time permits). Previous student’s works Taken from the previous student’s journal (Atulya Mahajan, Huan Keat (Sean) Toh): The device driver ran on Linux distribution 2.6.10 and 2.6.11. 2. The greyscale works correctly, but the color was fuzzy. 3. The cleanup function was inconsistent 4. Kernel panic when unload the module Our achievements Our device driver is stable with the 2.6.16.14 kernel works properly, consistently without errors( ie load module, unload module , auto-detect different devices, no kernel panic) (goal #1) Our driver supports Video4linux (goal #2) We improve the preview driver to support both grey scale and color cards (goal #3) Problems found in the original device driver and our solutions When compiled and executed the hrt module was loaded, but: No device was detected, The major number did not show up Sol: we put a series of debugging messages to test, and we add code in the hrt_init_module, hrt_cleanup_module, hrt_load, hrt_unload. 2. The two cards were detected as grayscale cards, and give us a warning message about sysfs needed. (Cont) Sol: Switched the two cards, reboot, and load module again. It works. We diagnose the cards slots are sensitive. Moreover, sysfs is not a main issue. The pci color card was not unregistered when we unload the module(this prob panic the kernel when unloading). First found by Danny Sol: we add lines o