modeset output permission denied

[yanyanbell]

hi, I'm encountering cannot set CRTC for connector 71 (13): Permission denied, I'm trying to use drmSetMaster to gain control over the hw, but this call remain gives me permission denied error. what could be the problem? Thank you in advance!

[yvm]

Do you have write permissions for dri file you trying to use?

[yanyanbell]

I found the problem is caused by x server. drmsetmaster cannot work with x-server. Thanks for your help