1 files changed, 34 insertions, 57 deletions

diff --git a/drivers/base/dd.c b/drivers/base/dd.c
index b25bcab2a26b..06ec0e851fa1 100644
--- a/drivers/base/dd.c
+++ b/drivers/base/dd.c
@@ -224,76 +224,52 @@ static int deferred_devs_show(struct seq_file *s, void *data)
 }
 DEFINE_SHOW_ATTRIBUTE(deferred_devs);
 
-static int deferred_probe_timeout = -1;
+#ifdef CONFIG_MODULES
+/*
+ * In the case of modules, set the default probe timeout to
+ * 30 seconds to give userland some time to load needed modules
+ */
+int driver_deferred_probe_timeout = 30;
+#else
+/* In the case of !modules, no probe timeout needed */
+int driver_deferred_probe_timeout = -1;
+#endif
+EXPORT_SYMBOL_GPL(driver_deferred_probe_timeout);
+
 static int __init deferred_probe_timeout_setup(char *str)
 {
 	int timeout;
 
 	if (!kstrtoint(str, 10, &timeout))
-		deferred_probe_timeout = timeout;
+		driver_deferred_probe_timeout = timeout;
 	return 1;
 }
 __setup("deferred_probe_timeout=", deferred_probe_timeout_setup);
 
-static int __driver_deferred_probe_check_state(struct device *dev)
-{
-	if (!initcalls_done)
-		return -EPROBE_DEFER;
-
-	if (!deferred_probe_timeout) {
-		dev_WARN(dev, "deferred probe timeout, ignoring dependency");
-		return -ETIMEDOUT;
-	}
-
-	return 0;
-}
-
 /**
  * driver_deferred_probe_check_state() - Check deferred probe state
  * @dev: device to check
  *
- * Returns -ENODEV if init is done and all built-in drivers have had a chance
- * to probe (i.e. initcalls are done), -ETIMEDOUT if deferred probe debug
- * timeout has expired, or -EPROBE_DEFER if none of those conditions are met.
+ * Return:
+ * -ENODEV if initcalls have completed and modules are disabled.
+ * -ETIMEDOUT if the deferred probe timeout was set and has expired
+ *  and modules are enabled.
+ * -EPROBE_DEFER in other cases.
  *
  * Drivers or subsystems can opt-in to calling this function instead of directly
  * returning -EPROBE_DEFER.
  */
 int driver_deferred_probe_check_state(struct device *dev)
 {
-	int ret;
-
-	ret = __driver_deferred_probe_check_state(dev);
-	if (ret < 0)
-		return ret;
-
-	dev_warn(dev, "ignoring dependency for device, assuming no driver");
-
-	return -ENODEV;
-}
-
-/**
- * driver_deferred_probe_check_state_continue() - check deferred probe state
- * @dev: device to check
- *
- * Returns -ETIMEDOUT if deferred probe debug timeout has expired, or
- * -EPROBE_DEFER otherwise.
- *
- * Drivers or subsystems can opt-in to calling this function instead of
- * directly returning -EPROBE_DEFER.
- *
- * This is similar to driver_deferred_probe_check_state(), but it allows the
- * subsystem to keep deferring probe after built-in drivers have had a chance
- * to probe. One scenario where that is useful is if built-in drivers rely on
- * resources that are provided by modular drivers.
- */
-int driver_deferred_probe_check_state_continue(struct device *dev)
-{
-	int ret;
+	if (!IS_ENABLED(CONFIG_MODULES) && initcalls_done) {
+		dev_warn(dev, "ignoring dependency for device, assuming no driver");
+		return -ENODEV;
+	}
 
-	ret = __driver_deferred_probe_check_state(dev);
-	if (ret < 0)
-		return ret;
+	if (!driver_deferred_probe_timeout) {
+		dev_WARN(dev, "deferred probe timeout, ignoring dependency");
+		return -ETIMEDOUT;
+	}
 
 	return -EPROBE_DEFER;
 }
@@ -302,7 +278,7 @@ static void deferred_probe_timeout_work_func(struct work_struct *work)
 {
 	struct device_private *private, *p;
 
-	deferred_probe_timeout = 0;
+	driver_deferred_probe_timeout = 0;
 	driver_deferred_probe_trigger();
 	flush_work(&deferred_probe_work);
 
@@ -336,9 +312,9 @@ static int deferred_probe_initcall(void)
 	driver_deferred_probe_trigger();
 	flush_work(&deferred_probe_work);
 
-	if (deferred_probe_timeout > 0) {
+	if (driver_deferred_probe_timeout > 0) {
 		schedule_delayed_work(&deferred_probe_timeout_work,
-			deferred_probe_timeout * HZ);
+			driver_deferred_probe_timeout * HZ);
 	}
 	return 0;
 }
@@ -668,9 +644,10 @@ static int really_probe_debug(struct device *dev, struct device_driver *drv)
  */
 int driver_probe_done(void)
 {
-	pr_debug("%s: probe_count = %d\n", __func__,
-		 atomic_read(&probe_count));
-	if (atomic_read(&probe_count))
+	int local_probe_count = atomic_read(&probe_count);
+
+	pr_debug("%s: probe_count = %d\n", __func__, local_probe_count);
+	if (local_probe_count)
 		return -EBUSY;
 	return 0;
 }
@@ -1222,7 +1199,7 @@ void driver_detach(struct device_driver *drv)
 			spin_unlock(&drv->p->klist_devices.k_lock);
 			break;
 		}
-		dev_prv = list_entry(drv->p->klist_devices.k_list.prev,
+		dev_prv = list_last_entry(&drv->p->klist_devices.k_list,
 				     struct device_private,
 				     knode_driver.n_node);
 		dev = dev_prv->device;