[CentOS] Troubleshooting suspend/resume problem in Centos 7

Tue Jul 15 10:16:05 UTC 2014
Emmanuel Noobadmin <centos.admin at gmail.com>

I'm trying out CentOS 7 using a HP AMD laptop
http://h10025.www1.hp.com/ewfrf/wc/document?cc=uk&lc=en&docname=c03877039

The problem is the laptop doesn't suspend properly in runlevel 5 /
graphical.target and following guides, I found that it suspends (power
LED blinking) but does not resume in runlevel 3 / multi-user.target.
When it locks up, the machine is unresponsive to ping/ssh so it's not
just a blank screen.

Unfortunately, the only applicable guide I found on troubleshooting
this is for Ubuntu, which requires the kernel to support pm_trace
which isn't found in /sys/power.

Since there is a big red warning on centos.org about
building/compiling my own kernel to add functions, I'm wondering if
there are any alternative method to troubleshoot the issue on CentOS.

I suspect it may be related to the Radeon GPU as I notice that every
now and then after fresh boot, the GUI desktop will freeze for a while
and dmesg will contain errors:
[drm:cik_ib_test] *ERROR* radeon: fence wait failed (-35)
[drm:radeon_ib_ring_tests] *ERROR* radeon: failed testing IB on ring 2 (-35)

As a side note, this laptop had no problems with suspend/resume when
it was running Ubuntu 14.04