Comment 33 for bug 1573959

Same issue here on multiple dell latitudes E6540 laptops in company (using Ubuntu 14.04.5). And it does happen after resuming from a suspend. Almost every open application is affected with distorted/missing letters. Looks like http://askubuntu.com/questions/584922/how-do-i-fix-fonts-not-rendering-and-missing-letters (intel driver issue?). Only restarting lightdm (or logging out and in again), fixed the situation.

root@tom-laptop:/home/tdesloovere# lshw -sanitize -numeric -C display
  *-display
       description: VGA compatible controller
       product: 4th Gen Core Processor Integrated Graphics Controller [8086:416]
       vendor: Intel Corporation [8086]
       physical id: 2
       bus info: pci@0000:00:02.0
       version: 06
       width: 64 bits
       clock: 33MHz
       capabilities: msi pm vga_controller bus_master cap_list rom
       configuration: driver=i915 latency=0
       resources: irq:33 memory:f5800000-f5bfffff memory:d0000000-dfffffff ioport:f000(size=64)

root@tom-laptop:/home/tdesloovere# lspci -vvnn -d 8086:416
00:02.0 VGA compatible controller [0300]: Intel Corporation 4th Gen Core Processor Integrated Graphics Controller [8086:0416] (rev 06) (prog-if 00 [VGA controller])
 Subsystem: Dell Device [1028:05be]
 Control: I/O+ Mem+ BusMaster+ SpecCycle- MemWINV- VGASnoop- ParErr- Stepping- SERR- FastB2B- DisINTx+
 Status: Cap+ 66MHz- UDF- FastB2B+ ParErr- DEVSEL=fast >TAbort- <TAbort- <MAbort- >SERR- <PERR- INTx-
 Latency: 0
 Interrupt: pin A routed to IRQ 33
 Region 0: Memory at f5800000 (64-bit, non-prefetchable) [size=4M]
 Region 2: Memory at d0000000 (64-bit, prefetchable) [size=256M]
 Region 4: I/O ports at f000 [size=64]
 Expansion ROM at <unassigned> [disabled]
 Capabilities: [90] MSI: Enable+ Count=1/1 Maskable- 64bit-
  Address: fee00018 Data: 0000
 Capabilities: [d0] Power Management version 2
  Flags: PMEClk- DSI+ D1- D2- AuxCurrent=0mA PME(D0-,D1-,D2-,D3hot-,D3cold-)
  Status: D0 NoSoftRst- PME-Enable- DSel=0 DScale=0 PME-
 Capabilities: [a4] PCI Advanced Features
  AFCap: TP+ FLR+
  AFCtrl: FLR-
  AFStatus: TP-
 Kernel driver in use: i915
root@tom-laptop:/home/tdesloovere# dpkg -l | grep xserver-xorg-video-intel-lts-xenial
ii xserver-xorg-video-intel-lts-xenial 2:2.99.917+git20160325-1ubuntu1~trusty1 amd64 X.Org X server -- Intel i8xx, i9xx display driver