Had it happen today for the first time. Other than Ubuntu updates no changes to the configuration in months so it seems to be a very recent change. The last time I used the dual monitor config was 5 days ago, with no troubles at all. Now the 2nd monitor (4k) goes blank and comes back about every 5 seconds. Tried resetting display resolution (and then back again) and may have helped for now.
Latest Dell XPS13 dev edition running Ubuntu 15.04. uname Linux crom 3.19.0-33-generic #38-Ubuntu SMP Fri Nov 6 18:18:12 UTC 2015 x86_64 x86_64 x86_64 GNU/Linux dmesg [27734.104083] [drm:gen8_irq_handler [i915_bpo]] *ERROR* The master control interrupt lied (SDE)! (many times) lspci 00:00.0 Host bridge: Intel Corporation Broadwell-U Host Bridge -OPI (rev 09) 00:02.0 VGA compatible controller: Intel Corporation Broadwell-U Integrated Graphics (rev 09) 00:03.0 Audio device: Intel Corporation Broadwell-U Audio Controller (rev 09) 00:04.0 Signal processing controller: Intel Corporation Broadwell-U Camarillo Device (rev 09) 00:14.0 USB controller: Intel Corporation Wildcat Point-LP USB xHCI Controller (rev 03) 00:16.0 Communication controller: Intel Corporation Wildcat Point-LP MEI Controller #1 (rev 03) 00:1b.0 Audio device: Intel Corporation Wildcat Point-LP High Definition Audio Controller (rev 03) 00:1c.0 PCI bridge: Intel Corporation Wildcat Point-LP PCI Express Root Port #1 (rev e3) 00:1c.3 PCI bridge: Intel Corporation Wildcat Point-LP PCI Express Root Port #4 (rev e3) 00:1d.0 USB controller: Intel Corporation Wildcat Point-LP USB EHCI Controller (rev 03) 00:1f.0 ISA bridge: Intel Corporation Wildcat Point-LP LPC Controller (rev 03) 00:1f.2 SATA controller: Intel Corporation Wildcat Point-LP SATA Controller [AHCI Mode] (rev 03) 00:1f.3 SMBus: Intel Corporation Wildcat Point-LP SMBus Controller (rev 03) 00:1f.6 Signal processing controller: Intel Corporation Wildcat Point-LP Thermal Management Controller (rev 03) 01:00.0 Unassigned class [ff00]: Realtek Semiconductor Co., Ltd. RTS5249 PCI Express Card Reader (rev 01) 02:00.0 Network controller: Broadcom Corporation BCM4352 802.11ac Wireless Network Adapter (rev 03) -- 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/1488719 Title: dmesg shows "[drm:gen8_irq_handler [i915]] *ERROR* The master control interrupt lied (SDE)!" Status in Linux: Fix Released Status in linux package in Ubuntu: Confirmed Bug description: On a recent intel NUC using i915 graphics, I get the following errors in dmesg: [drm:gen8_irq_handler [i915]] *ERROR* The master control interrupt lied (SDE)! There are two monitors connected to this box, one with mini- HDMI->HDMI, one with mini-DP->HDMI cable. Maybe related: https://bugs.freedesktop.org/show_bug.cgi?id=80896 ProblemType: Bug DistroRelease: Ubuntu 15.04 Package: linux-image-generic 3.19.0.26.25 ProcVersionSignature: Ubuntu 3.19.0-26.28-generic 3.19.8-ckt4 Uname: Linux 3.19.0-26-generic x86_64 ApportVersion: 2.17.2-0ubuntu1.3 Architecture: amd64 Date: Wed Aug 26 10:07:31 2015 InstallationDate: Installed on 2015-08-01 (24 days ago) InstallationMedia: Ubuntu 15.04 "Vivid Vervet" - Release amd64 (20150422) ProcKernelCmdLine: BOOT_IMAGE=/vmlinuz-3.19.0-26-generic.efi.signed root=/dev/mapper/ubuntu--vg-root ro quiet splash vt.handoff=7 SourcePackage: linux UdevLog: Error: [Errno 2] No such file or directory: '/var/log/udev' UpgradeStatus: No upgrade log present (probably fresh install) To manage notifications about this bug go to: https://bugs.launchpad.net/linux/+bug/1488719/+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