@@ -129,7 +129,29 @@ void driver_deferred_probe_del(struct device *dev)
 	mutex_unlock(&deferred_probe_mutex);
 }
 
+static bool driver_deferred_probe_report;
+
+/**
+ * dev_warn_deferred() - report why a probe has been deferred
+ */
+void dev_warn_deferred(struct device *dev, const char *fmt, ...)
+{
+	if (driver_deferred_probe_report) {
+		struct va_format vaf;
+		va_list ap;
+
+		va_start(ap, fmt);
+		vaf.fmt = fmt;
+		vaf.va = ≈
+
+		dev_warn(dev, "deferring probe: %pV", &vaf);
+		va_end(ap);
+	}
+}
+EXPORT_SYMBOL_GPL(dev_warn_deferred);
+
 static bool driver_deferred_probe_enable = false;
+
 /**
  * driver_deferred_probe_trigger() - Kick off re-probing deferred devices
  *

@@ -188,6 +210,13 @@ static int deferred_probe_initcall(void)
 	driver_deferred_probe_trigger();
 	/* Sort as many dependencies as possible before exiting initcalls */
 	flush_workqueue(deferred_wq);
+
+	/* Now one final round, reporting any devices that remain deferred */
+	driver_deferred_probe_report = true;
+	driver_deferred_probe_trigger();
+	/* Sort as many dependencies as possible before exiting initcalls */
+	flush_workqueue(deferred_wq);
+
 	return 0;
 }
 late_initcall(deferred_probe_initcall);

@@ -1997,8 +1997,8 @@ int genpd_dev_pm_attach(struct device *dev)
 
 	pd = of_genpd_get_from_provider(&pd_args);
 	if (IS_ERR(pd)) {
-		dev_dbg(dev, "%s() failed to find PM domain: %ld\n",
-			__func__, PTR_ERR(pd));
+		dev_warn_deferred(dev, "%s() failed to find PM domain: %ld\n",
+				  __func__, PTR_ERR(pd));
 		of_node_put(dev->of_node);
 		return -EPROBE_DEFER;
 	}

@@ -2026,6 +2026,9 @@ int genpd_dev_pm_attach(struct device *dev)
 	ret = pm_genpd_poweron(pd);
 
 out:
+	if (ret)
+		dev_warn_deferred(dev, "%s() deferring probe: %d\n",
+				  __func__, ret);
 	return ret ? -EPROBE_DEFER : 0;
 }
 EXPORT_SYMBOL_GPL(genpd_dev_pm_attach);

@@ -201,7 +201,14 @@ struct clk *clk_get(struct device *dev, const char *con_id)
 
 	if (dev) {
 		clk = __of_clk_get_by_name(dev->of_node, dev_id, con_id);
-		if (!IS_ERR(clk) || PTR_ERR(clk) = -EPROBE_DEFER)
+		if (IS_ERR(clk) && PTR_ERR(clk) = -EPROBE_DEFER) {
+			if (dev)
+				dev_warn_deferred(dev,
+						  "unable to locate clock for connection %s\n",
+						  con_id);
+			return clk;
+		}
+		if (!IS_ERR(clk))
 			return clk;
 	}
 

@@ -101,6 +101,11 @@ struct gpio_desc *of_get_named_gpiod_flags(struct device_node *np,
 	pr_debug("%s: parsed '%s' property of node '%s[%d]' - status (%d)\n",
 		 __func__, propname, np->full_name, index,
 		 PTR_ERR_OR_ZERO(gg_data.out_gpio));
+
+//	if (gg_data.out_gpio = -EPROBE_DEFER)
+//		of_warn_deferred(np, "%s: unable to locate GPIO for %s[%d]\n",
+//				 __func__, propname, index);
+
 	return gg_data.out_gpio;
 }
 

@@ -1785,7 +1785,7 @@ int dw_hdmi_bind(struct device *dev, struct device *master,
 		hdmi->ddc = of_find_i2c_adapter_by_node(ddc_node);
 		of_node_put(ddc_node);
 		if (!hdmi->ddc) {
-			dev_dbg(hdmi->dev, "failed to read ddc node\n");
+			dev_warn_deferred(hdmi->dev, "failed to read ddc node\n");
 			return -EPROBE_DEFER;
 		}
 

@@ -1899,7 +1899,7 @@ static int exynos_dsi_probe(struct platform_device *pdev)
 	ret = devm_regulator_bulk_get(dev, ARRAY_SIZE(dsi->supplies),
 				      dsi->supplies);
 	if (ret) {
-		dev_info(dev, "failed to get regulators: %d\n", ret);
+		dev_warn_deferred(dev, "failed to get regulators: %d\n", ret);
 		return -EPROBE_DEFER;
 	}
 

@@ -595,8 +595,9 @@ static int imx_ldb_bind(struct device *dev, struct device *master, void *data)
 				else
 					return -EPROBE_DEFER;
 				if (!channel->panel) {
-					dev_err(dev, "panel not found: %s\n",
-						remote->full_name);
+					dev_warn_deferred(dev,
+							  "panel not found: %s\n",
+							  remote->full_name);
 					return -EPROBE_DEFER;
 				}
 			}

@@ -42,7 +42,7 @@ static int dsi_get_phy(struct msm_dsi *msm_dsi)
 	of_node_put(phy_node);
 
 	if (!phy_pdev || !msm_dsi->phy) {
-		dev_err(&pdev->dev, "%s: phy driver is not ready\n", __func__);
+		dev_warn_deferred(&pdev->dev, "%s: phy driver is not ready\n", __func__);
 		return -EPROBE_DEFER;
 	}
 

@@ -1117,7 +1117,8 @@ static int msm_pdev_probe(struct platform_device *pdev)
 		dev = bus_find_device_by_name(&platform_bus_type,
 				NULL, devnames[i]);
 		if (!dev) {
-			dev_info(&pdev->dev, "still waiting for %s\n", devnames[i]);
+			dev_warn_deferred(&pdev->dev, "waiting for %s\n",
+					  devnames[i]);
 			return -EPROBE_DEFER;
 		}
 

@@ -600,7 +600,8 @@ int rcar_du_crtc_create(struct rcar_du_group *rgrp, unsigned int index)
 	if (!IS_ERR(clk)) {
 		rcrtc->extclock = clk;
 	} else if (PTR_ERR(rcrtc->clock) = -EPROBE_DEFER) {
-		dev_info(rcdu->dev, "can't get external clock %u\n", index);
+		dev_warn_deferred(rcdu->dev, "can't get external clock %u\n",
+				  index);
 		return -EPROBE_DEFER;
 	}
 

@@ -404,8 +404,11 @@ int of_irq_get(struct device_node *dev, int index)
 		return rc;
 
 	domain = irq_find_host(oirq.np);
-	if (!domain)
+	if (!domain) {
+		dev_warn_deferred(dev, "%s() failed to locate IRQ domain\n",
+				  __func__);
 		return -EPROBE_DEFER;
+	}
 
 	return irq_create_of_mapping(&oirq);
 }

@@ -1203,6 +1203,7 @@ static int mvebu_pcie_parse_port(struct mvebu_pcie *pcie,
 
 	reset_gpio = of_get_named_gpio_flags(child, "reset-gpios", 0, &flags);
 	if (reset_gpio = -EPROBE_DEFER) {
+		dev_warn_deferred(dev, "unable to find reset gpio\n");
 		ret = reset_gpio;
 		goto err;
 	}

@@ -741,8 +741,9 @@ static int add_setting(struct pinctrl *p, struct pinctrl_map const *map)
 		 * OK let us guess that the driver is not there yet, and
 		 * let's defer obtaining this pinctrl handle to later...
 		 */
-		dev_info(p->dev, "unknown pinctrl device %s in map entry, deferring probe",
-			map->ctrl_dev_name);
+		dev_warn_deferred(p->dev,
+				  "unknown pinctrl device %s in map entry, deferring probe",
+				  map->ctrl_dev_name);
 		return -EPROBE_DEFER;
 	}
 

@@ -115,8 +115,8 @@ static int dt_to_map_one_config(struct pinctrl *p, const char *statename,
 	for (;;) {
 		np_pctldev = of_get_next_parent(np_pctldev);
 		if (!np_pctldev || of_node_is_root(np_pctldev)) {
-			dev_info(p->dev, "could not find pctldev for node %s, deferring probe\n",
-				np_config->full_name);
+			dev_warn_deferred(p->dev, "could not find pctldev for node %s, deferring probe\n",
+					  np_config->full_name);
 			of_node_put(np_pctldev);
 			/* OK let's just assume this will appear later then */
 			return -EPROBE_DEFER;

@@ -1410,8 +1410,9 @@ static int regulator_resolve_supply(struct regulator_dev *rdev)
 		if (have_full_constraints()) {
 			r = dummy_regulator_rdev;
 		} else {
-			dev_err(dev, "Failed to resolve %s-supply for %s\n",
-				rdev->supply_name, rdev->desc->name);
+			dev_warn_deferred(dev,
+					  "Failed to resolve %s-supply for %s\n",
+					  rdev->supply_name, rdev->desc->name);
 			return -EPROBE_DEFER;
 		}
 	}

@@ -1087,6 +1087,7 @@ extern void device_shutdown(void);
 /* debugging and troubleshooting/diagnostic helpers. */
 extern const char *dev_driver_string(const struct device *dev);
 
+void dev_warn_deferred(struct device *dev, const char *fmt, ...);
 
 #ifdef CONFIG_PRINTK