dix/dispatch.c:4049: AttachOffloadGPU: Assertion `new->current_master == pScreen' failed.

[Paul Menzel]

Dear Linux folks,


On 08/10/17 15:14, Paul Menzel wrote:

> Getting Dell Precision 3620 systems with an Intel Skylake system 
> i7-6700K, and an external AMD graphics card, the X.Org server does not 
> start and hits an assert. The software stack is Linux 4.9.38 and 4.12.5, 
> X.Org server 1.19.3 and xf86-video-amdgpu 1.3.0.
> 
> ```
> $ lspci -nn -s 00:01.0
> 00:01.0 PCI bridge [0604]: Intel Corporation Skylake PCIe Controller 
> (x16) [8086:1901] (rev 07)
> $ lspci -nn -s 1:00.0
> 01:00.0 VGA compatible controller [0300]: Advanced Micro Devices, Inc. 
> [AMD/ATI] Bonaire [FirePro W5100] [1002:6649]
> ```
> 
> The monitor’s DVI cable and a DVI-to-DP adapter is plugged into the 
> DisplayPort port of the AMD graphics card. The TTY login screen can be 
> shortly seen before GDM tries to start.
> 
> Please find the last X.Org server messages below.
> 
> ```
> […]
> (II) Loading /usr/lib/xorg/modules/libfb.so
> (II) Module fb: vendor="X.Org Foundation"
>          compiled for 1.19.3, module version = 1.0.0
> (--) Depth 24 pixmap format is 32 bpp
> (==) modeset(G0): Backing store enabled
> (==) modeset(G0): Silken mouse enabled
> (II) modeset(G0): RandR 1.2 enabled, ignore the following RandR disabled 
> message.
> (==) modeset(G0): DPMS enabled
> (II) modeset(G0): [DRI2] Setup complete
> (II) modeset(G0): [DRI2]   DRI driver: i965
> (II) modeset(G0): [DRI2]   VDPAU driver: i965
> (II) AMDGPU(0): [DRI2] Setup complete
> (II) AMDGPU(0): [DRI2]   DRI driver: radeonsi
> (II) AMDGPU(0): [DRI2]   VDPAU driver: radeonsi
> (II) AMDGPU(0): Front buffer pitch: 6912 bytes
> (II) AMDGPU(0): SYNC extension fences enabled
> (II) AMDGPU(0): Present extension enabled
> (==) AMDGPU(0): DRI3 enabled
> (==) AMDGPU(0): Backing store enabled
> (II) AMDGPU(0): Direct rendering enabled
> (II) AMDGPU(0): Use GLAMOR acceleration.
> (II) AMDGPU(0): Acceleration enabled
> (==) AMDGPU(0): DPMS enabled
> (==) AMDGPU(0): Silken mouse enabled
> (II) AMDGPU(0): Set up textured video (glamor)
> (II) AMDGPU(0): RandR 1.2 enabled, ignore the following RandR disabled 
> message.
> (--) RandR disabled
> Xorg: 
> /dev/shm/bee-root/xorg-server/xorg-server-1.19.3-0/source/dix/dispatch.c:4049: 
> AttachOffloadGPU: Assertion `new->current_master == pScreen' failed.
> ```
> 
> The USB keyboard does not work, and the system has to be controlled 
> remotely over SSH. Plugging in the DisplayPort cable into the internal 
> Intel graphics ports the Linux messages can be seen, but nothing else 
> works. Stopping GDM does not bring back the TTY screen. The keyboard 
> still does work. Plugging the USB cable out and back in doesn’t fix it 
> either.
> 
> Trying to disable the internal Intel graphics card, did not fix the 
> problem either.

Blacklisting the module *i915* works around the problem.

Please tell me if you want me to create a bug report for this issue, 
and, if yes, what part in the graphics stack this problem belongs to.


Kind regards,

Paul