I have to revise the upper report a bit. On my computer, the kernel bug seems to be reproducible with the same source location. As it turned out today, it does NOT NECESSARILY come after lightdm restart. So, it may or may not be connected to the invisible cursor issue. Pasting from dmesg:
WARNING: CPU: 0 PID: 2597 at /build/linux-1dujk3/linux-4.2.0/drivers/gpu/drm/i915/i915_gem.c:5269 i915_gem_track_fb+0x129/0x140 [i915]() WARN_ON(!(old->frontbuffer_bits & frontbuffer_bits)) -- You received this bug notification because you are a member of Ubuntu Touch seeded packages, which is subscribed to lightdm in Ubuntu. https://bugs.launchpad.net/bugs/1453538 Title: Invisible mouse pointer Status in Light Display Manager: Confirmed Status in lightdm package in Ubuntu: Triaged Bug description: After system boot on login screen mouse pointer is invisible. I am able to click to gadgets but its blind clicking. I dont know where is mouse pointer. When I'm switch to virtual console (CTRL+ALT+F1) and type sudo service lightdm restart command LightDM restarts and mouse pointer back to normal. ProblemType: Bug DistroRelease: Ubuntu 15.04 Package: lightdm 1.14.0-0ubuntu2 ProcVersionSignature: Ubuntu 3.19.0-17.17-lowlatency 3.19.6 Uname: Linux 3.19.0-17-lowlatency x86_64 ApportVersion: 2.17.2-0ubuntu1 Architecture: amd64 CurrentDesktop: Unity Date: Sun May 10 14:27:50 2015 InstallationDate: Installed on 2015-02-13 (85 days ago) InstallationMedia: Ubuntu 14.10 "Utopic Unicorn" - Release amd64 (20141022.1) LightdmConfig: [SeatDefaults] allow-guest = false SourcePackage: lightdm UpgradeStatus: Upgraded to vivid on 2015-04-25 (15 days ago) To manage notifications about this bug go to: https://bugs.launchpad.net/lightdm/+bug/1453538/+subscriptions -- Mailing list: https://launchpad.net/~touch-packages Post to : touch-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~touch-packages More help : https://help.launchpad.net/ListHelp