drm/i915: Remove DAC disable in CRT force detect on IGDNG

This is not required on newer stepping hardware to get
reliable force detect status. Removing this fixes screen
blank flicker in CRT detect on IGDNG.

Cc: Stable Team <stable@kernel.org>
Signed-off-by: Zhenyu Wang <zhenyuw@linux.intel.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>

diff --git a/drivers/gpu/drm/i915/intel_crt.c b/drivers/gpu/drm/i915/intel_crt.c
index 88814fa2dfd213427d556d091aa36f933bf08980..212e22740fc123e4a569a1e84e7445ae8a9de135 100644 (file)
--- a/drivers/gpu/drm/i915/intel_crt.c
+++ b/drivers/gpu/drm/i915/intel_crt.c
@@ -179,13 +179,10 @@ static bool intel_igdng_crt_detect_hotplug(struct drm_connector *connector)
 {
        struct drm_device *dev = connector->dev;
        struct drm_i915_private *dev_priv = dev->dev_private;
-       u32 adpa, temp;
+       u32 adpa;
        bool ret;
 
-       temp = adpa = I915_READ(PCH_ADPA);
-
-       adpa &= ~ADPA_DAC_ENABLE;
-       I915_WRITE(PCH_ADPA, adpa);
+       adpa = I915_READ(PCH_ADPA);
 
        adpa &= ~ADPA_CRT_HOTPLUG_MASK;
 
@@ -212,8 +209,6 @@ static bool intel_igdng_crt_detect_hotplug(struct drm_connector *connector)
        else
                ret = false;
 
-       /* restore origin register */
-       I915_WRITE(PCH_ADPA, temp);
        return ret;
 }