I confirm this bug is present on Ubuntu 18.04, my hardware is an Intel HD Graphics 5500.
It was working fine on the previous LTS, 16.04; if I use kernel 4.4.0-161-generic from Ubuntu 16 Xenial I can boot Ubuntu 18 Bionic fine, thus I conclude it's something in the kernel. I have tried these options (individually) without any effect: i915.enable_ips=0 swiotlb=force i915.enable_ips=0 intel_idle.max_cstate=1 i915.enable_rc6=0 i915.enable_psr=0 On the good kernel I see this error in dmesg: [drm:intel_dp_link_training_channel_equalization [i915]] *ERROR* failed to train DP, aborting While on the bad one there are no such failures as it detects everything: [ 10.429894] input: HDA Intel HDMI HDMI/DP,pcm=3 as /devices/pci0000:00/0000:00:03.0/sound/card0/input22 [ 10.429989] input: HDA Intel HDMI HDMI/DP,pcm=7 as /devices/pci0000:00/0000:00:03.0/sound/card0/input23 [ 10.430070] input: HDA Intel HDMI HDMI/DP,pcm=8 as /devices/pci0000:00/0000:00:03.0/sound/card0/input24 [ 10.430166] input: HDA Intel HDMI HDMI/DP,pcm=9 as /devices/pci0000:00/0000:00:03.0/sound/card0/input25 [ 10.430250] input: HDA Intel HDMI HDMI/DP,pcm=10 as /devices/pci0000:00/0000:00:03.0/sound/card0/input26 The most interesting clue to find a solution is however to be found in gparted-live-1.0.0-5-amd64.iso: when booting this live distro via USB I get exactly the same flickering (it uses kernel 5.2.0) but when starting Xorg the problem disappears. Switching back to any VT shows the flickering problem. I was wondering if it could be possible to dissect the GParted live ISO to find out what makes it work when starting Xorg. -- You received this bug notification because you are a member of Kernel Packages, which is subscribed to linux in Ubuntu. https://bugs.launchpad.net/bugs/1712508 Title: Disappearing screen and flickering after upgrade to 16.04 Status in linux package in Ubuntu: Confirmed Bug description: I have two Lenovo T410s that I upgraded from 14.04 to 16.04. Since then, one is working fine while the other shows mainly an ever disappearing screen and flickering. I have asked here: https://askubuntu.com/questions/947233/i-upgraded-from-kubuntu-14-04-lts-to-16-04-lts-and-now-my-screen-shows-up-and-di?noredirect=1#comment1506995_947233 I also found I am not the only one: https://askubuntu.com/questions/927407/flickering-screen-with-intel-graphics-on-ubuntu-17-04?noredirect=1#comment1507937_927407 The latter has tried pretty much that could be tried already, to no avail. I think that I can help with this problem, since my two T410s are identical in hard- and software, including BIOS, except that one is a type 2924 (with NVIDIA-card, though disabled in the BIOS), and the other one is a 2904 (without NVIDIA card). I have checked for differences at boot time and found DMAR as major difference: T410s, 2924: [ 0.335616] DMAR: Disabling batched IOTLB flush on Ironlake T410s, 2904: [ 0.355681] DMAR: BIOS has allocated no shadow GTT; disabling IOMMU for graphics Should this be initially at the root of the problem, I'd consider the kernel package as responsible, therefore I marked it as above. The outputs of lspci -k | grep -EA3 'VGA|3D|Display' are identical to the point. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1712508/+subscriptions -- Mailing list: https://launchpad.net/~kernel-packages Post to : kernel-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~kernel-packages More help : https://help.launchpad.net/ListHelp
