drm/radeon: rework audio option

In 3.12 I changed audio to be enabled by default,
but you still had to turn it on via xrandr.  This
was confusing to users so change it to minic the
previous behavior:

- audio option is set to -1 (auto) by default which is
  the current 3.12 behavior (audio is enabled but requires
  xrandr to turn it on).
- if audio = 1, the audio is enabled without needing
  to mess with xrandr (previous behavior)
- audio = 0 disables audio

It retains the new feature of allowing the user to enable
audio on the fly with xrandr, but turns audio on
automatically if radeon.audio=1 is set which is what
most users expect.

Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
diff --git a/drivers/gpu/drm/radeon/atombios_encoders.c b/drivers/gpu/drm/radeon/atombios_encoders.c
index 2a761f2..5e891b2 100644
--- a/drivers/gpu/drm/radeon/atombios_encoders.c
+++ b/drivers/gpu/drm/radeon/atombios_encoders.c
@@ -707,24 +707,37 @@
 	switch (connector->connector_type) {
 	case DRM_MODE_CONNECTOR_DVII:
 	case DRM_MODE_CONNECTOR_HDMIB: /* HDMI-B is basically DL-DVI; analog works fine */
-		if ((radeon_connector->audio == RADEON_AUDIO_ENABLE) ||
-		    (drm_detect_hdmi_monitor(radeon_connector->edid) &&
-		     (radeon_connector->audio == RADEON_AUDIO_AUTO)))
-			return ATOM_ENCODER_MODE_HDMI;
-		else if (radeon_connector->use_digital)
+		if (radeon_audio != 0) {
+			if (radeon_connector->use_digital &&
+			    (radeon_connector->audio == RADEON_AUDIO_ENABLE))
+				return ATOM_ENCODER_MODE_HDMI;
+			else if (drm_detect_hdmi_monitor(radeon_connector->edid) &&
+				 (radeon_connector->audio == RADEON_AUDIO_AUTO))
+				return ATOM_ENCODER_MODE_HDMI;
+			else if (radeon_connector->use_digital)
+				return ATOM_ENCODER_MODE_DVI;
+			else
+				return ATOM_ENCODER_MODE_CRT;
+		} else if (radeon_connector->use_digital) {
 			return ATOM_ENCODER_MODE_DVI;
-		else
+		} else {
 			return ATOM_ENCODER_MODE_CRT;
+		}
 		break;
 	case DRM_MODE_CONNECTOR_DVID:
 	case DRM_MODE_CONNECTOR_HDMIA:
 	default:
-		if ((radeon_connector->audio == RADEON_AUDIO_ENABLE) ||
-		    (drm_detect_hdmi_monitor(radeon_connector->edid) &&
-		     (radeon_connector->audio == RADEON_AUDIO_AUTO)))
-			return ATOM_ENCODER_MODE_HDMI;
-		else
+		if (radeon_audio != 0) {
+			if (radeon_connector->audio == RADEON_AUDIO_ENABLE)
+				return ATOM_ENCODER_MODE_HDMI;
+			else if (drm_detect_hdmi_monitor(radeon_connector->edid) &&
+				 (radeon_connector->audio == RADEON_AUDIO_AUTO))
+				return ATOM_ENCODER_MODE_HDMI;
+			else
+				return ATOM_ENCODER_MODE_DVI;
+		} else {
 			return ATOM_ENCODER_MODE_DVI;
+		}
 		break;
 	case DRM_MODE_CONNECTOR_LVDS:
 		return ATOM_ENCODER_MODE_LVDS;
@@ -732,14 +745,19 @@
 	case DRM_MODE_CONNECTOR_DisplayPort:
 		dig_connector = radeon_connector->con_priv;
 		if ((dig_connector->dp_sink_type == CONNECTOR_OBJECT_ID_DISPLAYPORT) ||
-		    (dig_connector->dp_sink_type == CONNECTOR_OBJECT_ID_eDP))
+		    (dig_connector->dp_sink_type == CONNECTOR_OBJECT_ID_eDP)) {
 			return ATOM_ENCODER_MODE_DP;
-		else if ((radeon_connector->audio == RADEON_AUDIO_ENABLE) ||
-			 (drm_detect_hdmi_monitor(radeon_connector->edid) &&
-			  (radeon_connector->audio == RADEON_AUDIO_AUTO)))
-			return ATOM_ENCODER_MODE_HDMI;
-		else
+		} else if (radeon_audio != 0) {
+			if (radeon_connector->audio == RADEON_AUDIO_ENABLE)
+				return ATOM_ENCODER_MODE_HDMI;
+			else if (drm_detect_hdmi_monitor(radeon_connector->edid) &&
+				 (radeon_connector->audio == RADEON_AUDIO_AUTO))
+				return ATOM_ENCODER_MODE_HDMI;
+			else
+				return ATOM_ENCODER_MODE_DVI;
+		} else {
 			return ATOM_ENCODER_MODE_DVI;
+		}
 		break;
 	case DRM_MODE_CONNECTOR_eDP:
 		return ATOM_ENCODER_MODE_DP;