No answer, just some further things to look at or try. I can use xxd
-e
on files in that directory without problem, though I don't have the
file you are looking for since I use radeon.
On my system everything in there is 444 permissions, except
directories.
What does your system show for ls -nZ?
# ls -nZ amdgpu_gca_config
-r--r--r--. 1 0 0 system_u:object_r:debugfs_t:s0 0 Dec 28 14:18 amdgpu_gca_config
Can less open the file after warning you about binary data? Can you
cat them into pipe to xxd?
cat amd_gca_config | xxd -e -
# cat amdgpu_gca_config | xxd -e -
cat: amdgpu_gca_config: Operation not permitted
What if you direct the output to someplace like your home directory?
xxd -e amd_gca_config ~/amd_gca_config.hexdump
Maybe write isn't permitted in those directories.
# xxd -e amdgpu_gca_config > ~/amd_gca_config.hexdump
xxd: amdgpu_gca_config: Operation not permitted
[root@localhost 0]# echo 'foobar' > ~/amd_gca_config.hexdump