Hi,
I just tried 3.15-rc6. I encountered a pretty nasty problem, which is
after suspending to RAM the system doesn't wake up properly. v3.14 is fine.
On wakeup all seems fine, i.e. hd starts to spin an USB-stuff wakes up.
But all I get from the graphics card is a white screen slowly filling
with random colored pixels. I had to hard reset the system.

I attached the kernel log, the X-servers log, lspci-output and my kernel
config.

Regards
Malte