Comment 96 for bug 814325

Ah ok, that makes more sense. Does this patch change anything? We might be disabling LVDS incorrectly (i.e. without a corresponding panel power sequence):

diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_d
index 35364e6..ab8a36d 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -1394,7 +1394,7 @@ static void intel_disable_pch_ports(struct drm_i915_privat
        val = I915_READ(reg);
        if (ADPA_PIPE_ENABLED(val, pipe))
                I915_WRITE(reg, val & ~ADPA_DAC_ENABLE);
-
+#if 0
        reg = PCH_LVDS;
        val = I915_READ(reg);
        if (LVDS_PIPE_ENABLED(val, pipe)) {
@@ -1402,7 +1402,7 @@ static void intel_disable_pch_ports(struct drm_i915_privat
                POSTING_READ(reg);
                udelay(100);
        }
-
+#endif
        disable_pch_hdmi(dev_priv, pipe, HDMIB);
        disable_pch_hdmi(dev_priv, pipe, HDMIC);
        disable_pch_hdmi(dev_priv, pipe, HDMID);