https://bugs.freedesktop.org/show_bug.cgi?id=85801

Bug ID: 85801 Summary: [Mobility Radeon HD 4570] Enabling HDMI monitor fails with kernel versions 3.17/3.16 Product: DRI Version: unspecified Hardware: x86-64 (AMD64) OS: Linux (All) Status: NEW Severity: major Priority: medium Component: DRM/Radeon Assignee: dri-devel@lists.freedesktop.org Reporter: CE.Mohammad.AlSaleh@gmail.com

Created attachment 108839 --> https://bugs.freedesktop.org/attachment.cgi?id=108839&action=edit dmesg output with the relevant call trace

With kernel version 3.17.2, when I connect my HDMI monitor, it shows up correctly in xrandr. But when I try to enable it, Xorg freezes and becomes a zombie process, and the HDMI monitor stays blank. dmesg hints radeon kernel code is at fault (attached).

Luckily, the system does not completely freeze. I can still connect to the system through ssh. So I can provide more information if needed.

I remember having similar issues with 3.16 when I tried it. I'm currently using 3.15.5 which does not suffer from this bug.