[pkg-cinnamon] Bug#780553: additional information

[Andrew Assim]

I discovered the Software rendering mode of cinnamon does not have the
same problem. With software rendering, cinnamon is using 260% of the CPU
and system is not very usable. 

00:02.0 VGA compatible controller: Intel Corporation Core Processor
Integrated Graphics Controller (rev 02)

modinfo i915:

filename:       /lib/modules/3.16.0-4-amd64/kernel/drivers/gpu/drm/i915/i915.ko
license:        GPL and additional rights
description:    Intel Graphics
author:         Tungsten Graphics, Inc.
depends:        drm_kms_helper,drm,i2c-core,video,button,i2c-algo-bit
intree:         Y
vermagic:       3.16.0-4-amd64 SMP mod_unload modversions 
parm:           modeset:Use kernel modesetting [KMS] (0=DRM_I915_KMS
from .config, 1=on, -1=force vga console preference [default]) (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:           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:           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:           enable_ppgtt:Override PPGTT usage. (-1=auto [default],
0=disabled, 1=aliasing, 2=full) (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:           prefault_disable:Disable page prefaulting for
pread/pwrite/reloc (default:false). For developers only. (bool)
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 at lists.freedesktop.org, if your machine needs it. It will then
be included in an upcoming module version. (int)
parm:           disable_display:Disable display (default: false) (bool)
parm:           disable_vtd_wa:Disable all VT-d workarounds (default:
false) (bool)
parm:           enable_cmd_parser:Enable command parsing (1=enabled
[default], 0=disabled) (int)