https://bugs.freedesktop.org/show_bug.cgi?id=109692
--- Comment #8 from Tom St Denis tom.stdenis@amd.com --- Just a follow up. If you "chmod +s" umr as a non-root user then even if you sudo it it won't have permissions to read the debugfs files.
Make sure you "sudo chmod +s" the binary or simply just "sudo umr".