drm/i915: Fix HDMI mode select for Cougarpoint PCH

For real HDMI sink, CPT HDMI port has to set 'HDMI' mode flag
in order to make HDMI audio work correctly.

This is required patch for drm/i915 to enable HDMI audio on CPT PCH,
ALSA patch is at http://mailman.alsa-project.org/pipermail/alsa-devel/2010-May/027601.html

Tested-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Zhenyu Wang <zhenyuw@linux.intel.com>
Signed-off-by: Eric Anholt <eric@anholt.net>

2 files changed, 7 insertions, 1 deletions

diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
index df7224de0aed..881fbe9a17f2 100644
--- a/drivers/gpu/drm/i915/i915_reg.h
+++ b/drivers/gpu/drm/i915/i915_reg.h
@@ -2744,6 +2744,9 @@
 #define  SDVO_ENCODING          (0)
 #define  TMDS_ENCODING          (2 << 10)
 #define  NULL_PACKET_VSYNC_ENABLE       (1 << 9)
+/* CPT */
+#define  HDMI_MODE_SELECT       (1 << 9)
+#define  DVI_MODE_SELECT        (0)
 #define  SDVOB_BORDER_ENABLE    (1 << 7)
 #define  AUDIO_ENABLE           (1 << 6)
 #define  VSYNC_ACTIVE_HIGH      (1 << 4)
diff --git a/drivers/gpu/drm/i915/intel_hdmi.c b/drivers/gpu/drm/i915/intel_hdmi.c
index 65727f0a79a3..83bd764b000e 100644
--- a/drivers/gpu/drm/i915/intel_hdmi.c
+++ b/drivers/gpu/drm/i915/intel_hdmi.c
@@ -59,8 +59,11 @@ static void intel_hdmi_mode_set(struct drm_encoder *encoder,
                 SDVO_VSYNC_ACTIVE_HIGH |
                 SDVO_HSYNC_ACTIVE_HIGH;
 
-        if (hdmi_priv->has_hdmi_sink)
+        if (hdmi_priv->has_hdmi_sink) {
                 sdvox |= SDVO_AUDIO_ENABLE;
+                if (HAS_PCH_CPT(dev))
+                        sdvox |= HDMI_MODE_SELECT;
+        }
 
         if (intel_crtc->pipe == 1) {
                 if (HAS_PCH_CPT(dev))