i965 (Sandy Bridge) misses blitImage functionality (please add it)
NAME="Ubuntu" VERSION="20.04.2 LTS (Focal Fossa)" ID=ubuntu ID_LIKE=debian PRETTY_NAME="Ubuntu 20.04.2 LTS" VERSION_ID="20.04" HOME_URL="https://www.ubuntu.com/" SUPPORT_URL="https://help.ubuntu.com/" BUG_REPORT_URL="https://bugs.launchpad.net/ubuntu/" PRIVACY_POLICY_URL="https://www.ubuntu.com/legal/terms-and-policies/privacy-policy" VERSION_CODENAME=focal UBUNTU_CODENAME=focal
*-display description: VGA compatible controller product: Whistler [Radeon HD 6730M/6770M/7690M XT] [1002:6740] vendor: Advanced Micro Devices, Inc. [AMD/ATI]  physical id: 0 bus info: pci@0000:01:00.0 version: 00 width: 64 bits clock: 33MHz capabilities: pm pciexpress msi vga_controller bus_master cap_list rom configuration: driver=radeon latency=0 resources: irq:50 memory:90000000-9fffffff memory:a8800000-a881ffff ioport:2000(size=256) memory:a8820000-a883ffff *-display description: Display controller product: 2nd Generation Core Processor Family Integrated Graphics Controller [8086:102] vendor: Intel Corporation  physical id: 2 bus info: pci@0000:00:02.0 version: 09 width: 64 bits clock: 33MHz capabilities: msi pm bus_master cap_list configuration: driver=i915 latency=0 resources: irq:49 memory:a8000000-a83fffff memory:a0000000-a7ffffff ioport:3000(size=64)
- Kernel version:
Linux test-iMac 5.4.0-66-generic #74-Ubuntu SMP Wed Jan 27 22:54:38 UTC 2021 x86_64 x86_64 x86_64 GNU/Linux
- Mesa version:
name of display: :0 display: :0 screen: 0 direct rendering: Yes Extended renderer info (GLX_MESA_query_renderer): Vendor: X.Org (0x1002) Device: AMD TURKS (DRM 2.50.0 / 5.4.0-66-generic, LLVM 11.0.0) (0x6740) Version: 20.2.6 Accelerated: yes Video memory: 512MB Unified memory: no Preferred profile: core (0x1) Max core profile version: 3.3 Max compat profile version: 3.1 Max GLES1 profile version: 1.1 Max GLES profile version: 3.1 Memory info (GL_ATI_meminfo): VBO free memory - total: 511 MB, largest block: 511 MB VBO free aux. memory - total: 1021 MB, largest block: 1021 MB Texture free memory - total: 511 MB, largest block: 511 MB Texture free aux. memory - total: 1021 MB, largest block: 1021 MB Renderbuffer free memory - total: 511 MB, largest block: 511 MB Renderbuffer free aux. memory - total: 1021 MB, largest block: 1021 MB Memory info (GL_NVX_gpu_memory_info): Dedicated video memory: 512 MB Total available memory: 1533 MB Currently available dedicated video memory: 511 MB OpenGL vendor string: X.Org OpenGL renderer string: AMD TURKS (DRM 2.50.0 / 5.4.0-66-generic, LLVM 11.0.0) OpenGL core profile version string: 3.3 (Core Profile) Mesa 20.2.6 OpenGL core profile shading language version string: 3.30 OpenGL core profile context flags: (none) OpenGL core profile profile mask: core profile OpenGL version string: 3.1 Mesa 20.2.6 OpenGL shading language version string: 1.40 OpenGL context flags: (none) OpenGL ES profile version string: OpenGL ES 3.1 Mesa 20.2.6 OpenGL ES profile shading language version string: OpenGL ES GLSL ES 3.10
- Xserver version:
X.Org X Server 1.20.9 X Protocol Version 11, Revision 0 Build Operating System: Linux 4.15.0-130-generic x86_64 Ubuntu Current Operating System: Linux test-iMac 5.4.0-66-generic #74-Ubuntu SMP Wed Jan 27 22:54:38 UTC 2021 x86_64 Kernel command line: ro root=UUID=0611c7b6-3d07-4592-b622-d3240df90979 initrd=boot\initrd.img-5.4.0-66-generic Build Date: 17 January 2021 09:13:31AM xorg-server 2:1.20.9-2ubuntu1.2~20.04.1 (For technical support please see http://www.ubuntu.com/support) Current version of pixman: 0.38.4 Before reporting problems, check http://wiki.x.org to make sure that you have the latest version.
- Desktop manager and compositor:
After intensive research I can confirm that the i965 driver lacks the
blitImage functionality. That feature seems to be necessary on (some) multi GPU systems. Without a proper
blitImage support, the alternative GPU cannot be used. More information regarding this matter can be found at the following bug report here (check comment 12 by AMD developer Michel Dänzer):
In my case, if I enforce the use of the second (Intel) iGPU with
/etc/environment, the X server is crashing right before a new login attempt is performed (restart of X). The only thing which is visible (for a very short time) is the mouse cursor. That behavior is 100% reproducible and occurs every time when the use of the second iGPU is enforced.
That problem seems to exist (in different form) also at other systems. https://github.com/lutris/agora/issues/22
No alternative solution or workaround exists to fix this problem. Switching off the integrated Intel iGPU in the UEFI firmware may help in certain situations to avoid that some gaming software like Lutris may work incorrectly.
some GPU related DMESG logs
libGL error: Different GPU, but blitImage not implemented for this driver libGL error: failed to load driver: i965
[ 1.279421] i915 0000:00:02.0: BAR 6: can't assign [??? 0x00000000 flags 0x20000000] (bogus alignment) [ 1.279422] [drm] Failed to find VBIOS tables (VBT)
The used system is an Apple iMac 12,2 which contains two GPUs. Linux is running in UEFI mode. In contrast to most other systems, the discrete Radeon graphics is the main GPU 0. The Intel Sandy Bridge HD iGPU is the second GPU 1. It seems that Apple did not intend to use the built-in GPU on those computers. So a further problem may be an incomplete setup or "activation" of the iGPU in the Apple EFI firmware.
I have found in my logs a "firmware bug" called note which may be also relevant here:
[ 1.030982] [Firmware Bug]: ACPI(GFX0) defines _DOD but not _DOS
According to the following ACPI 5.0 information, the
_DOD function seems to be needed for "output switching" (aka GPU switching?) and not the
_DOS one. (https://docs.microsoft.com/en-us/windows-hardware/drivers/bringup/other-acpi-namespace-objects). Well, this is my understanding of that quite complex topic. It could also be different. ;-)