At the very top of my screen there is a thin flashing pink line, and all the virtual consoles sport several multi-colored vertical flashing lines, and the console text flickers.
Some specs:
I installed Ubuntu 14.04 LTS on a Toshiba Satellite L75 B7270. From this url (http://releases.ubuntu.com/14.04/) I downloaded the image file with this description: “PC (Intel x86) desktop image For almost all PCs. This includes most machines with Intel/AMD/etc type processors and almost all computers that run Microsoft Windows, as well as newer Apple Macintosh systems based on Intel processors. Choose this if you are at all unsure.” I disabled Secure Boot, and switched from UEFI to CSM.
So far I've attempted a few simple suggested remedies with no-to-little luck. I switched from lightdm to gdm. Nada. I tried to use the xrandr command to change the refresh rate, and a refresh rate of 60 is the only available option. I tried using the “Multimedia Systems Selector” to tinker with there Default Output. No effect. I had I guess what you could call partial success when I booted with nomodeset. The flickering line in my gui was gone and the virtual terminals were fine, but as a commenter noted here (What does `nomodeset` do), performance takes a hit. Every window I move displays a trail, the windows fade in and out in a weirdly jerky manner, and scrolling text in (for instance) Firefox is jerky and hard on the eyes. This is hardly an ideal “solution.”
Here's the output of some informative commands:
$ uname -a
3.13.0-32-generic #57-Ubuntu SMP Tue Jul 15 03:51:12 UTC 2014 i686 i686 i686 GNU/Linux
$ lshw -c video
*-display
description: VGA compatible controller
product: Haswell-ULT Integrated Graphics Controller
vendor: Intel Corporation
physical id: 2
bus info: pci@0000:00:02.0
version: 0b
width: 64 bits
clock: 33MHz
capabilities: msi pm vga_controller bus_master cap_list rom
configuration: driver=i915 latency=0
resources: irq:61 memory:b0000000-b03fffff memory:a0000000-afffffff ioport:4000(size=64)
modinfo i915 (some output omitted)
intree: Y
vermagic: 3.13.0-32-generic SMP mod_unload modversions 686
signer: Magrathea: Glacier signing key
sig_key: A7:FC:65:90:FC:4A:8D:85:9A:AE:BD:A2:CA:5D:D0:47:16:24:4F:A0
sig_hashalgo: sha512
parm: invert_brightness:Invert backlight brightness (-1 force normal, 0 machine defaults, 1 force inversion), please report PCI device ID, subsystem vendor and subsystem device ID to dri-devel@lists.freedesktop.org, if your machine needs it. It will then be included in an upcoming module version. (int)
parm: modeset:Use kernel modesetting [KMS] (0=DRM_I915_KMS from .config, 1=on, -1=force vga console preference [default]) (int)
parm: fbpercrtc:int
parm: panel_ignore_lid:Override lid status (0=autodetect, 1=autodetect disabled [default], -1=force lid closed, -2=force lid open) (int)
parm: powersave:Enable powersavings, fbc, downclocking, etc. (default: true) (int)
parm: semaphores:Use semaphores for inter-ring sync (default: -1 (use per-chip defaults)) (int)
parm: i915_enable_rc6:Enable power-saving render C-state 6. Different stages can be selected via bitmask values (0 = disable; 1 = enable rc6; 2 = enable deep rc6; 4 = enable deepest rc6). For example, 3 would enable rc6 and deep rc6, and 7 would enable everything. default: -1 (use per-chip default) (int)
parm: i915_enable_fbc:Enable frame buffer compression for power savings (default: -1 (use per-chip default)) (int)
parm: lvds_downclock:Use panel (LVDS/eDP) downclocking for power savings (default: false) (int)
parm: lvds_channel_mode:Specify LVDS channel mode (0=probe BIOS [default], 1=single-channel, 2=dual-channel) (int)
parm: lvds_use_ssc:Use Spread Spectrum Clock with panels [LVDS/eDP] (default: auto from VBT) (int)
parm: vbt_sdvo_panel_type:Override/Ignore selection of SDVO panel mode in the VBT (-2=ignore, -1=auto [default], index in VBT BIOS table) (int)
parm: reset:Attempt GPU resets (default: true) (bool)
parm: enable_hangcheck:Periodically check GPU activity for detecting hangs. WARNING: Disabling this can cause system wide hangs. (default: true) (bool)
parm: i915_enable_ppgtt:Enable PPGTT (default: true) (int)
parm: enable_psr:Enable PSR (default: false) (int)
parm: preliminary_hw_support:Enable preliminary hardware support. (int)
parm: disable_power_well:Disable the power well when possible (default: true) (int)
parm: enable_ips:Enable IPS (default: true) (int)
parm: fastboot:Try to skip unnecessary mode sets at boot time (default: false) (bool)
parm: enable_pc8:Enable support for low power package C states (PC8+) (default: true) (int)
parm: pc8_timeout:Number of msecs of idleness required to enter PC8+ (default: 5000) (int)
parm: prefault_disable:Disable page prefaulting for pread/pwrite/reloc (default:false). For developers only. (bool)
$ lspci -v
00:02.0 VGA compatible controller: Intel Corporation Haswell-ULT Integrated Graphics Controller (rev 0b) (prog-if 00 [VGA controller])
Subsystem: Toshiba America Info Systems Device f931
Flags: bus master, fast devsel, latency 0, IRQ 61
Memory at b0000000 (64-bit, non-prefetchable) [size=4M]
Memory at a0000000 (64-bit, prefetchable) [size=256M]
I/O ports at 4000 [size=64]
Expansion ROM at <unassigned> [disabled]
Capabilities: [90] MSI: Enable+ Count=1/1 Maskable- 64bit-
Capabilities: [d0] Power Management version 2
Capabilities: [a4] PCI Advanced Features
Kernel driver in use: i915
I gratefully welcome all advice, and remind those hardcore Linux junkies out there that since my level of knowledge is best described as modest, a bit of explanation may sometimes be required to get your message across.
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I eventually installed the AMD64 version and enabled UEFI. The flickering issue persisted.
