I've made a live bootable pendrive to test the issue. I've found that it's not present when I boot a live OS, so something must have gone wrong during the upgrade. I've attached glxinfo outputs.
thinkpad-glxinfo-livecd.txt: How it looks like when I boot from USB drive. It's normal. OpenGL vendor string: Intel Open Source Technology Center OpenGL renderer string: Mesa DRI Mobile IntelĀ® GM45 Express Chipset OpenGL version string: 2.1 Mesa 18.0.0-rc5 OpenGL shading language version string: 1.20 thinkpad-glxinfo-normalboot.txt: How it looks like when I boot my usual system on the same hardware. Software rendering is enforced. OpenGL vendor string: VMware, Inc. OpenGL renderer string: llvmpipe (LLVM 6.0, 128 bits) OpenGL version string: 3.0 Mesa 18.0.0-rc5 OpenGL shading language version string: 1.30 ** Attachment added: "thinkpad-glxinfo-livecd.txt" https://bugs.launchpad.net/ubuntu/+source/xorg/+bug/1770913/+attachment/5141596/+files/thinkpad-glxinfo-livecd.txt -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1770913 Title: Software rendering is forced after 18.04 upgrade To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/xorg/+bug/1770913/+subscriptions -- ubuntu-bugs mailing list [email protected] https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
