tree 13814c13ad49b68bb1a2d930bad14a30cc5fc241
parent 539526b4137bc0e7a8806c38c8522f226814a0e6
author Takashi Iwai <tiwai@suse.de> 1355222789 +0100
committer Daniel Vetter <daniel.vetter@ffwll.ch> 1355226830 +0100

drm/i915: Fix shifted screen on top of LVDS on IVY laptop

The commit [23670b322: drm/i915: CPT+ pch transcoder workaround]
caused a regression on some HP laptops with IvyBridge.  The whole
laptop screen is shifted downward for a few pixels constantly.
The problem appears only on LVDS while DP and VGA seem unaffected.
Also, the problem disappears once when go and back from S3.
(S4 resume still shows the same problem.)

This patch revives the minimum part the commit above dropped.
For fixing this regression, only the setup of CHICKEN2 bit in
cpt_init_clock_gating() is needed.

Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>