drm/i915/dp: downstream port capabilities are not present in DPCD 1.0

We haven't read the downstream port caps for DPCD 1.0, so don't use
them.

v2: use defines for DPCD 1.0 downstream port types

Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Reviewed-by: Adam Jackson <ajax@redhat.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>

1 files changed, 14 insertions, 6 deletions

diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
index 60d2006fe15d..605908df95d8 100644
--- a/drivers/gpu/drm/i915/intel_dp.c
+++ b/drivers/gpu/drm/i915/intel_dp.c
@@ -2810,7 +2810,6 @@ static enum drm_connector_status
 intel_dp_detect_dpcd(struct intel_dp *intel_dp)
 {
         uint8_t *dpcd = intel_dp->dpcd;
-        bool hpd;
         uint8_t type;
 
         if (!intel_dp_get_dpcd(intel_dp))
@@ -2821,8 +2820,8 @@ intel_dp_detect_dpcd(struct intel_dp *intel_dp)
                 return connector_status_connected;
 
         /* If we're HPD-aware, SINK_COUNT changes dynamically */
-        hpd = !!(intel_dp->downstream_ports[0] & DP_DS_PORT_HPD);
-        if (hpd) {
+        if (intel_dp->dpcd[DP_DPCD_REV] >= 0x11 &&
+            intel_dp->downstream_ports[0] & DP_DS_PORT_HPD) {
                 uint8_t reg;
                 if (!intel_dp_aux_native_read_retry(intel_dp, DP_SINK_COUNT,
                                                     &reg, 1))
@@ -2836,9 +2835,18 @@ intel_dp_detect_dpcd(struct intel_dp *intel_dp)
                 return connector_status_connected;
 
         /* Well we tried, say unknown for unreliable port types */
-        type = intel_dp->downstream_ports[0] & DP_DS_PORT_TYPE_MASK;
-        if (type == DP_DS_PORT_TYPE_VGA || type == DP_DS_PORT_TYPE_NON_EDID)
-                return connector_status_unknown;
+        if (intel_dp->dpcd[DP_DPCD_REV] >= 0x11) {
+                type = intel_dp->downstream_ports[0] & DP_DS_PORT_TYPE_MASK;
+                if (type == DP_DS_PORT_TYPE_VGA ||
+                    type == DP_DS_PORT_TYPE_NON_EDID)
+                        return connector_status_unknown;
+        } else {
+                type = intel_dp->dpcd[DP_DOWNSTREAMPORT_PRESENT] &
+                        DP_DWN_STRM_PORT_TYPE_MASK;
+                if (type == DP_DWN_STRM_PORT_TYPE_ANALOG ||
+                    type == DP_DWN_STRM_PORT_TYPE_OTHER)
+                        return connector_status_unknown;
+        }
 
         /* Anything else is out of spec, warn and ignore */
         DRM_DEBUG_KMS("Broken DP branch device, ignoring\n");