https://bugs.freedesktop.org/show_bug.cgi?id=99851 --- Comment #30 from erhard_f@mailbox.org --- The same problem on my machine: # dmesg | grep -i drm [ 11.753729] [drm] radeon kernel modesetting enabled. [ 11.760535] [drm] initializing kernel modesetting (CEDAR 0x1002:0x68F9 0x1787:0x2291 0x00). [ 11.767360] [drm] register mmio base: 0x80140000 [ 11.770683] [drm] register mmio size: 131072 [ 11.899433] [drm] GPU not posted. posting now... [ 11.903067] [drm] Detected VRAM RAM=512M, BAR=256M [ 11.903068] [drm] RAM width 64bits DDR [ 11.934284] [drm] radeon: 512M of VRAM memory ready [ 11.936547] [drm] radeon: 1024M of GTT memory ready. [ 11.938855] [drm] Loading CEDAR Microcode [ 13.060828] [drm] Internal thermal controller with fan control [ 13.075872] [drm] radeon: dpm initialized [ 13.099787] [drm] GART: num cpu pages 262144, num gpu pages 262144 [ 13.151601] [drm] PCIE GART of 1024M enabled (table at 0x000000000014C000). [ 13.166212] [drm] Supports vblank timestamp caching Rev 2 (21.10.2013). [ 13.166214] [drm] Driver supports precise vblank timestamp query. [ 13.166323] [drm] radeon: irq initialized. [ 13.377755] [drm:0xd000000001d22d04] *ERROR* radeon: ring 0 test failed (scratch(0x8504)=0xCAFEDEAD) # inxi -b System: Host: T801 Kernel: 4.11.1-gentoo ppc64 (32 bit) Console: tty 0 Distro: Gentoo Base System release 2.3 Machine: No /sys/class/dmi; using dmidecode: dmidecode is not installed. CPU: Dual core PPC970MP altivec supported (-MCP-) speed/max: 2300.000000MHz/2300 MHz Graphics: Card-1: NVIDIA NV43 [GeForce 6600] Card-2: Advanced Micro Devices [AMD/ATI] Cedar [Radeon HD 5000/6000/7350/8350 Series] Display Server: X.org 1.19.3 drivers: fbdev,ati,radeon,nouveau tty size: 211x52 Advanced Data: N/A for root out of X But I can confirm the ring test succeeds on kernel 4.10.16. I will try to bisect starting from the 4.11-rcs. -- You are receiving this mail because: You are the assignee for the bug.