I'm using
libdrm in effort to change gamma on my Chromebook. I find that when I call
drmModeCrtcSetGamma, I get a "Permission denied" error, regardless of whether I run my program with
sudo. (See line 91 of
my source code.)
So I insert a call to
drmSetMaster(dat->fd) above
drmModeCrtcSetGamma, and that results in an "Invalid argument" error. What is the correct approach, please? Documentation seems rather sparse, with the best I've seen being
this.
