drm/i915: Check max number of lanes when registering DDI ports
DDI A and E share some of the lanes, so check that we have enough
lanes for the purpose we need before registering the encoders.
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1449597590-6971-3-git-send-email-ville.syrjala@linux.intel.com
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
diff --git a/drivers/gpu/drm/i915/intel_ddi.c b/drivers/gpu/drm/i915/intel_ddi.c
index 612400f..a69db46 100644
--- a/drivers/gpu/drm/i915/intel_ddi.c
+++ b/drivers/gpu/drm/i915/intel_ddi.c
@@ -3282,6 +3282,33 @@
struct intel_encoder *intel_encoder;
struct drm_encoder *encoder;
bool init_hdmi, init_dp;
+ int max_lanes;
+
+ if (I915_READ(DDI_BUF_CTL(PORT_A)) & DDI_A_4_LANES) {
+ switch (port) {
+ case PORT_A:
+ max_lanes = 4;
+ break;
+ case PORT_E:
+ max_lanes = 0;
+ break;
+ default:
+ max_lanes = 4;
+ break;
+ }
+ } else {
+ switch (port) {
+ case PORT_A:
+ max_lanes = 2;
+ break;
+ case PORT_E:
+ max_lanes = 2;
+ break;
+ default:
+ max_lanes = 4;
+ break;
+ }
+ }
init_hdmi = (dev_priv->vbt.ddi_port_info[port].supports_dvi ||
dev_priv->vbt.ddi_port_info[port].supports_hdmi);
@@ -3292,6 +3319,15 @@
return;
}
+ if (WARN(max_lanes == 0,
+ "No lanes for port %c\n", port_name(port)))
+ return;
+
+ if (WARN(init_hdmi && max_lanes < 4,
+ "Not enough lanes (%d) for HDMI on port %c\n",
+ max_lanes, port_name(port)))
+ init_hdmi = false;
+
intel_dig_port = kzalloc(sizeof(*intel_dig_port), GFP_KERNEL);
if (!intel_dig_port)
return;