On a Ubuntu/precise AMD64 host I pulled in drm-intel-next-queued into latest upstream v3.4-rc6+ (commit d60b9c16d7) GIT tree.
Just FYI: I have reverted commit 2e7a44814d802c8ba479164b8924070cd908d6b5 "drm/i915: Do no set Stencil Cache eviction LRA w/a on gen7+".

I have seen this on a Samsung ultrabook series-5 of my parents with sandy-bridge CPU.

With this kernel I see the following ERRORs:

$ dmesg | egrep -i 'drm|i915'
[    8.523203] [drm] Initialized drm 1.1.0 20060810
[    9.421698] i915 0000:00:02.0: setting latency timer to 64
[    9.505114] i915 0000:00:02.0: irq 48 for MSI/MSI-X
[    9.505125] [drm] Supports vblank timestamp caching Rev 1 (10.10.2010).
[    9.505127] [drm] Driver supports precise vblank timestamp query.
[   10.145126] [drm] Enabling RC6 states: RC6 on, RC6p off, RC6pp off
[   10.331637] fb: conflicting fb hw usage inteldrmfb vs VESA VGA - removing generic driver
[   10.332447] fbcon: inteldrmfb (fb0) is primary device
[   10.642321] fb0: inteldrmfb frame buffer device
[   10.642324] drm: registered panic notifier
[   10.649789] [drm] Initialized i915 1.6.0 20080730 for 0000:00:02.0 on minor 0
[   19.420808] [drm:gen6_sanitize_pm] *ERROR* Power management discrepancy: GEN6_RP_INTERRUPT_LIMITS expected 17000000, was 12060000
[   45.531903] [drm:gen6_sanitize_pm] *ERROR* Power management discrepancy: GEN6_RP_INTERRUPT_LIMITS expected 00070000, was 17000000

I will attach full dmesg and lspci -nn as requested by bwidawsk on #intel-gfx.

Regards,
- Sedat -