/dev/dri/card0 gives ENOTTY error

[Shailendra Gupta]

Hi;
  I have written a driver based on DRM and created equivalent .ko file. The file I insmod are drm.ko, drm_kms_helper.ko and mydrm.ko. It calls my probe function and loads mydrm.ko, and also creates card0 in /dev folder.
 
In user space I call the function ret = drmAvailable(). The result is as follows: It seems it calls preclose because drmAvailable calls close(fd) before exiting. drmAvailable also send the Version IOCTL to DRM. In My case it returns the error number of 0x19 = 25, which corresponds to ENOTTY. Please suggest me how to remove this error and make the ioctls successful.

++++drm_release
+++++Shailendra: drm_platform_preclose -- Called
 +++ Shailendra: drm_platform_lastclose -- Called

drmOpenDevice:  buf = /dev/dri/card0
--drmOpenDevice: open result is 5, (OK)
drmOpenDevice will return now with fd = 0x5
drmAvailable - before calling drmGetVersion

API: drmGetVersion  DRM_IOCTL_VERSION = 0xc0246400
drmIoctl fd = 0x5 request = 0xc0246400  errno = 0x19

Thanks and Regards
Shailendra