driver core: Better distinguish probe errors in really_probe

really_probe tries to special case errors from ->probe, but due to all
other initialization added to the function over time now a lot of
internal errors hit that code path as well.  Untangle that by adding
a new probe_err local variable and apply the special casing only to
that.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Kirti Wankhede <kwankhede@nvidia.com>
Link: https://lore.kernel.org/r/20210617142218.1877096-3-hch@lst.deSigned-off-by: Alex Williamson <alex.williamson@redhat.com>

drivers/base/dd.c

@@ -513,12 +513,44 @@ static ssize_t state_synced_show(struct device *dev,
 }
 static DEVICE_ATTR_RO(state_synced);
 
+
+static int call_driver_probe(struct device *dev, struct device_driver *drv)
+{
+	int ret = 0;
+
+	if (dev->bus->probe)
+		ret = dev->bus->probe(dev);
+	else if (drv->probe)
+		ret = drv->probe(dev);
+
+	switch (ret) {
+	case 0:
+		break;
+	case -EPROBE_DEFER:
+		/* Driver requested deferred probing */
+		dev_dbg(dev, "Driver %s requests probe deferral\n", drv->name);
+		break;
+	case -ENODEV:
+	case -ENXIO:
+		pr_debug("%s: probe of %s rejects match %d\n",
+			 drv->name, dev_name(dev), ret);
+		break;
+	default:
+		/* driver matched but the probe failed */
+		pr_warn("%s: probe of %s failed with error %d\n",
+			drv->name, dev_name(dev), ret);
+		break;
+	}
+
+	return ret;
+}
+
 static int really_probe(struct device *dev, struct device_driver *drv)
 {
-	int ret = -EPROBE_DEFER;
 	int local_trigger_count = atomic_read(&deferred_trigger_count);
 	bool test_remove = IS_ENABLED(CONFIG_DEBUG_TEST_DRIVER_REMOVE) &&
 			   !drv->suppress_bind_attrs;
+	int ret = -EPROBE_DEFER, probe_ret = 0;
 
 	if (defer_all_probes) {
 		/*
@@ -572,13 +604,13 @@ static int really_probe(struct device *dev, struct device_driver *drv)
 			goto probe_failed;
 	}
 
-	if (dev->bus->probe) {
-		ret = dev->bus->probe(dev);
-		if (ret)
-			goto probe_failed;
-	} else if (drv->probe) {
-		ret = drv->probe(dev);
-		if (ret)
+	probe_ret = call_driver_probe(dev, drv);
+	if (probe_ret) {
+		/*
+		 * Ignore errors returned by ->probe so that the next driver can
+		 * try its luck.
+		 */
+		ret = 0;
 		goto probe_failed;
 	}
 
@@ -650,28 +682,8 @@ static int really_probe(struct device *dev, struct device_driver *drv)
 		dev->pm_domain->dismiss(dev);
 	pm_runtime_reinit(dev);
 	dev_pm_set_driver_flags(dev, 0);
-
-	switch (ret) {
-	case -EPROBE_DEFER:
-		/* Driver requested deferred probing */
-		dev_dbg(dev, "Driver %s requests probe deferral\n", drv->name);
+	if (probe_ret == -EPROBE_DEFER)
 		driver_deferred_probe_add_trigger(dev, local_trigger_count);
-		break;
-	case -ENODEV:
-	case -ENXIO:
-		pr_debug("%s: probe of %s rejects match %d\n",
-			 drv->name, dev_name(dev), ret);
-		break;
-	default:
-		/* driver matched but the probe failed */
-		pr_warn("%s: probe of %s failed with error %d\n",
-			drv->name, dev_name(dev), ret);
-	}
-	/*
-	 * Ignore errors returned by ->probe so that the next driver can try
-	 * its luck.
-	 */
-	ret = 0;
 done:
 	atomic_dec(&probe_count);
 	wake_up_all(&probe_waitqueue);