https://bugzilla.kernel.org/show_bug.cgi?id=98751
Bug ID: 98751 Summary: radeon: multihead "no signal" on one of the monitors - regression Product: Drivers Version: 2.5 Kernel Version: 4.0.3+ Hardware: All OS: Linux Tree: Mainline Status: NEW Severity: high Priority: P1 Component: Video(DRI - non Intel) Assignee: drivers_video-dri@kernel-bugs.osdl.org Reporter: mikkeloscar@gmail.com Regression: No
Since this commit: https://git.kernel.org/cgit/linux/kernel/git/stable/linux-stable.git/commit/... one of my two monitors doesn't get a signal (it just says "no signal").
The monitors are connected to a Radeon HD 6990 card. One is connected through HDMI and one through DVI. I'm using the radeon driver.
Most of the time it is the monitor connected through HDMI which doesn't get a signal, but I was able to switch it around somehow by messing around with screen orientation in X (not quite sure how to replicate or if it's even relevant).
I tried to revert the commit in kernel 4.0.4 (latest I tried) and that solves the problem for me.