After Vega 56/64 GPU hang I unable reboot system

[Mikhail Gavrilov]

On Thu, 20 Dec 2018 at 21:20, StDenis, Tom <Tom.StDenis at amd.com> wrote:
>
> Sorry I didn't mean to be dismissive.  It's just not a bug in umr though.
>
> On Fedora I can access those files as root just fine:
>
> tom at fx8:~$ sudo bash
> [sudo] password for tom:
> root at fx8:/home/tom# cd /sys/kernel/debug/dri/0
> root at fx8:/sys/kernel/debug/dri/0# xxd -e amdgpu_gca_config
> 00000000: 00000003 00000001 00000004 0000000b  ................
> 00000010: 00000001 00000002 00000004 00000100  ................
> 00000020: 00000020 00000008 00000020 00000100   ....... .......
> 00000030: 00000030 000004c0 00000000 00000003  0...............
> 00000040: 00000000 00000000 00000000 00000000  ................
> 00000050: 00000000 00000000 24000042 00000002  ........B..$....
> 00000060: 00000001 00004100 017f9fcf 0000008e  .....A..........
> 00000070: 00000001 000015dd 000000c6 0000d000  ................
> 00000080: 00001458                             X...
> root at fx8:/sys/kernel/debug/dri/0#
>
> There must be some sort of ACL or something going on here.
>
> Tom
>

Tom, which Fedora version do you tried and with which kernel?
I am tried several kernels from old 4.19-rc2 to fresh 4.20-rc7 and
every time when I tried run `# cat
/sys/kernel/debug/dri/0/amdgpu_gca_config` I got message that
"Operation not permitted".
I try understand difference with our setups. If you use default kernel
it means that kernel options between our setups are same. Difference
only in hardware and mounted file systems.

P.S. I am also tried ask how to manage ACL in debugfs in
platform-driver-x86 mail list, but no one answer.

--
Best Regards,
Mike Gavrilov.