return (memcmp(old_edid->raw_edid, new_edid->raw_edid, new_edid->length) == 0);
 }
 
+bool wait_for_alt_mode(struct dc_link *link)
+{
+
+       /**
+        * something is terribly wrong if time out is > 200ms. (5Hz)
+        * 500 microseconds * 400 tries us 200 ms
+        **/
+       unsigned int sleep_time_in_microseconds = 500;
+       unsigned int tries_allowed = 400;
+       bool is_in_alt_mode;
+       unsigned long long enter_timestamp;
+       unsigned long long finish_timestamp;
+       unsigned long long time_taken_in_ns;
+       int tries_taken;
+
+       DC_LOGGER_INIT(link->ctx->logger);
+
+       if (link->link_enc->funcs->is_in_alt_mode == NULL)
+               return true;
+
+       is_in_alt_mode = link->link_enc->funcs->is_in_alt_mode(link->link_enc);
+       DC_LOG_WARNING("DP Alt mode state on HPD: %d\n", is_in_alt_mode);
+
+       if (is_in_alt_mode)
+               return true;
+
+       enter_timestamp = dm_get_timestamp(link->ctx);
+
+       for (tries_taken = 0; tries_taken < tries_allowed; tries_taken++) {
+               udelay(sleep_time_in_microseconds);
+               /* ask the link if alt mode is enabled, if so return ok */
+               if (link->link_enc->funcs->is_in_alt_mode(link->link_enc)) {
+
+                       finish_timestamp = dm_get_timestamp(link->ctx);
+                       time_taken_in_ns = dm_get_elapse_time_in_ns(
+                               link->ctx, finish_timestamp, enter_timestamp);
+                       DC_LOG_WARNING("Alt mode entered finished after %llu ms\n",
+                                      time_taken_in_ns / 1000000);
+                       return true;
+               }
+
+       }
+       finish_timestamp = dm_get_timestamp(link->ctx);
+       time_taken_in_ns = dm_get_elapse_time_in_ns(link->ctx, finish_timestamp,
+                                                   enter_timestamp);
+       DC_LOG_WARNING("Alt mode has timed out after %llu ms\n",
+                       time_taken_in_ns / 1000000);
+       return false;
+}
+
 /**
  * dc_link_detect() - Detect if a sink is attached to a given link
  *
                }
 
                case SIGNAL_TYPE_DISPLAY_PORT: {
+                       /* wa HPD high coming too early*/
+                       if (link->link_enc->features.flags.bits.DP_IS_USB_C == 1) {
+
+                               /* if alt mode times out, return false */
+                               if (wait_for_alt_mode(link) == false) {
+                                       return false;
+                               }
+                       }
+
                        if (!detect_dp(
                                link,
                                &sink_caps,