Created attachment 182011 [details] dmesg $ lspci | grep VGA 00:02.0 VGA compatible controller: Intel Corporation 3rd Gen Core processor Graphics Controller (rev 09) 01:00.0 VGA compatible controller: Advanced Micro Devices, Inc. [AMD/ATI] Wimbledon XT [Radeon HD 7970M] (rev ff) See attached dmesg for the complete error. First thing that I find strange is Direct firmware load for radeon/TAHITI_vce.bin failed with error -2 1. This file is not in upstream linux-firmware git repository yet. I've seen it here https://secure.freedesktop.org/~agd5f/radeon_ucode/ and put it into /usr/lib/firmware/radeon, but the message and null pointer dereference doesn't change at all. 2. I don't have a TAHITI GPU, I have a PITCAIRN GPU. There is __pm_runtime_disable in the stack trace so I tried booting with radeon.runpm=0 radeon.dpm=0 (as in the attached dmesg), but the exact same thing happens with and without power management. Symptoms: Boot is extremely slow and X.org completely hangs on startup. It should so some interaction with the radeon GPU on startup, i.e. waking it up from runpm for a short time, perhaps there is the cause in its hang.
Created attachment 182021 [details] dmesg from linux 4.1 for comparison
I built agd5's drm-fixes-4.2-wip and the issue is gone. I haven't tested which commit fixed it but I guess this could have had something to do with it: http://cgit.freedesktop.org/~agd5f/linux/commit/?h=drm-fixes-4.2-wip&id=05995ea6b002dffa1831212435689b7802de5be1 I will close this when rc2 is out and it's still gone.
Okay, fixed in rc2. Thanks.