drm/i915: don't rely on previous values set on DDI_BUF_CTL

Just set the only bit we need, everything else is either ignored on
HDMI or should be set to zero.

Signed-off-by: Paulo Zanoni <paulo.r.zanoni@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

1 files changed, 1 insertions, 5 deletions

diff --git a/drivers/gpu/drm/i915/intel_ddi.c b/drivers/gpu/drm/i915/intel_ddi.c
index ab48083ffcec..9a95beafc507 100644
--- a/drivers/gpu/drm/i915/intel_ddi.c
+++ b/drivers/gpu/drm/i915/intel_ddi.c
@@ -1017,16 +1017,12 @@ void intel_enable_ddi(struct intel_encoder *encoder)
         struct drm_i915_private *dev_priv = dev->dev_private;
         struct intel_hdmi *intel_hdmi = enc_to_intel_hdmi(&encoder->base);
         int port = intel_hdmi->ddi_port;
-        u32 temp;
-
-        temp = I915_READ(DDI_BUF_CTL(port));
-        temp |= DDI_BUF_CTL_ENABLE;
 
         /* Enable DDI_BUF_CTL. In HDMI/DVI mode, the port width,
          * and swing/emphasis values are ignored so nothing special needs
          * to be done besides enabling the port.
          */
-        I915_WRITE(DDI_BUF_CTL(port), temp);
+        I915_WRITE(DDI_BUF_CTL(port), DDI_BUF_CTL_ENABLE);
 }
 
 void intel_disable_ddi(struct intel_encoder *encoder)