DRM RGA 方式做图形转换，mmap 报非法参数 22， 请指教。

1. 
   

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1. int main(int argc, char **argv)
   
2. {
   
3.     std::cout << "     ------->1" << std::endl;
   
4.     int fd;
   
5.     drmModeConnector *conn;
   
6.     drmModeRes *res;
   
7.     uint32_t conn_id;
   
8.     uint32_t crtc_id;
   
9. 
   
10.     fd = open("/dev/dri/card0", O_RDWR | O_CLOEXEC);
    
11.     std::cout << "     ------->2" << std::endl;
    

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1. struct drm_mode_create_dumb create = {};
   
2. struct drm_mode_map_dumb map = {};
   
3. 
   
4. /* create a dumb-buffer, the pixel format is XRGB888 */
   
5. create.width = bo->width;
   
6. create.height = bo->height;
   
7. create.bpp = 32;
   
8. drmIoctl(fd, DRM_IOCTL_MODE_CREATE_DUMB, &create);
   
9. std::cout << " ------->b" << std::endl;
   
10. 
    
11. /* bind the dumb-buffer to an FB object */
    
12. bo->pitch = create.pitch;
    
13. bo->size = create.size;
    
14. bo->handle = create.handle;
    
15. drmModeAddFB(fd, bo->width, bo->height, 24, 32, bo->pitch,
    
16. bo->handle, &bo->fb_id);
    
17. 
    
18. std::cout << " ------->a" << std::endl;
    
19. /* map the dumb-buffer to userspace */
    
20. map.handle = create.handle;
    
21. drmIoctl(fd, DRM_IOCTL_MODE_MAP_DUMB, &map);
    
22. 
    
23. std::cout << " ------->size..." << create.size <<std::endl;
    
24. 
    
25. bo->vaddr = (unsigned char* )mmap(0, create.size, PROT_READ | PROT_WRITE,
    
26. MAP_PRIVATE, fd, map.offset);
    
27. 
    
28. if(bo->vaddr == MAP_FAILED) {
    
29. std::cout << " ------->c fail..." << errno <<std::endl;
    
30. }
    
31. 
    
32. std::cout << " ------->c" << std::endl;
    
33. 
    

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