drm/i915: set the LPT FDI RX polarity reversal bit when needed
authorPaulo Zanoni <paulo.r.zanoni@intel.com>
Sat, 1 Dec 2012 14:04:26 +0000 (12:04 -0200)
committerDaniel Vetter <daniel.vetter@ffwll.ch>
Mon, 10 Dec 2012 10:14:29 +0000 (11:14 +0100)
commit68d18ad7fbc16288aa230ec0ffb4416fd4363c87
tree24d670effc303e0f849480cdd872aeaabcfbae4a
parentdde86e2db54545ef981b64805097a7b4c3156d6e
drm/i915: set the LPT FDI RX polarity reversal bit when needed

If we fail to set the bit when needed we get some nice FDI link
training failures (AKA "black screen on VGA output").

While we don't really know how to properly choose whether we need to
set the bit or not (VBT?), just read the initial value set by the BIOS
and store it for later usage.

Signed-off-by: Paulo Zanoni <paulo.r.zanoni@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
drivers/gpu/drm/i915/i915_drv.h
drivers/gpu/drm/i915/i915_reg.h
drivers/gpu/drm/i915/intel_crt.c
drivers/gpu/drm/i915/intel_ddi.c