drm/i915: Check VBT for port presence in addition to the strap on VLV/CHV

Apparently some CHV boards failed to hook up the port presence straps
for HDMI ports as well (earlier we assumed this problem only affected
eDP ports). So let's check the VBT in addition to the strap, and if
either one claims that the port is present go ahead and register the
relevant connector.

While at it, change port D to register DP before HDMI as we do for ports
B and C since
commit 457c52d87e5d ("drm/i915: Only ignore eDP ports that are connected")

Also print a debug message when we register a HDMI connector to aid
in diagnosing missing/incorrect ports. We already had such a print for
DP/eDP.

v2: Improve the comment in the code a bit, note the port D change in
    the commit message

Cc: Radoslav Duda <radosd@radosd.com>
Tested-by: Radoslav Duda <radosd@radosd.com>
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=96321
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1464945463-14364-1-git-send-email-ville.syrjala@linux.intel.com
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>

1 files changed, 21 insertions, 9 deletions

diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index 60cba1956c0d..6eceefb2ceb4 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -14702,7 +14702,7 @@ static void intel_setup_outputs(struct drm_device *dev)
 		if (I915_READ(PCH_DP_D) & DP_DETECTED)
 			intel_dp_init(dev, PCH_DP_D, PORT_D);
 	} else if (IS_VALLEYVIEW(dev) || IS_CHERRYVIEW(dev)) {
-		bool has_edp;
+		bool has_edp, has_port;
 
 		/*
 		 * The DP_DETECTED bit is the latched state of the DDC
@@ -14712,25 +14712,37 @@ static void intel_setup_outputs(struct drm_device *dev)
 		 * Thus we can't rely on the DP_DETECTED bit alone to detect
 		 * eDP ports. Consult the VBT as well as DP_DETECTED to
 		 * detect eDP ports.
+		 *
+		 * Sadly the straps seem to be missing sometimes even for HDMI
+		 * ports (eg. on Voyo V3 - CHT x7-Z8700), so check both strap
+		 * and VBT for the presence of the port. Additionally we can't
+		 * trust the port type the VBT declares as we've seen at least
+		 * HDMI ports that the VBT claim are DP or eDP.
 		 */
 		has_edp = intel_dp_is_edp(dev, PORT_B);
-		if (I915_READ(VLV_DP_B) & DP_DETECTED || has_edp)
+		has_port = intel_bios_is_port_present(dev_priv, PORT_B);
+		if (I915_READ(VLV_DP_B) & DP_DETECTED || has_port)
 			has_edp &= intel_dp_init(dev, VLV_DP_B, PORT_B);
-		if (I915_READ(VLV_HDMIB) & SDVO_DETECTED && !has_edp)
+		if ((I915_READ(VLV_HDMIB) & SDVO_DETECTED || has_port) && !has_edp)
 			intel_hdmi_init(dev, VLV_HDMIB, PORT_B);
 
 		has_edp = intel_dp_is_edp(dev, PORT_C);
-		if (I915_READ(VLV_DP_C) & DP_DETECTED || has_edp)
+		has_port = intel_bios_is_port_present(dev_priv, PORT_C);
+		if (I915_READ(VLV_DP_C) & DP_DETECTED || has_port)
 			has_edp &= intel_dp_init(dev, VLV_DP_C, PORT_C);
-		if (I915_READ(VLV_HDMIC) & SDVO_DETECTED && !has_edp)
+		if ((I915_READ(VLV_HDMIC) & SDVO_DETECTED || has_port) && !has_edp)
 			intel_hdmi_init(dev, VLV_HDMIC, PORT_C);
 
 		if (IS_CHERRYVIEW(dev)) {
-			/* eDP not supported on port D, so don't check VBT */
-			if (I915_READ(CHV_HDMID) & SDVO_DETECTED)
-				intel_hdmi_init(dev, CHV_HDMID, PORT_D);
-			if (I915_READ(CHV_DP_D) & DP_DETECTED)
+			/*
+			 * eDP not supported on port D,
+			 * so no need to worry about it
+			 */
+			has_port = intel_bios_is_port_present(dev_priv, PORT_D);
+			if (I915_READ(CHV_DP_D) & DP_DETECTED || has_port)
 				intel_dp_init(dev, CHV_DP_D, PORT_D);
+			if (I915_READ(CHV_HDMID) & SDVO_DETECTED || has_port)
+				intel_hdmi_init(dev, CHV_HDMID, PORT_D);
 		}
 
 		intel_dsi_init(dev);