3 files changed, 76 insertions, 34 deletions

diff --git a/drivers/base/firmware_class.c b/drivers/base/firmware_class.c
index 60290671f04a..72c644b191a4 100644
--- a/drivers/base/firmware_class.c
+++ b/drivers/base/firmware_class.c
@@ -81,6 +81,11 @@ enum {
 
 static int loading_timeout = 60;	/* In seconds */
 
+static inline long firmware_loading_timeout(void)
+{
+	return loading_timeout > 0 ? loading_timeout * HZ : MAX_SCHEDULE_TIMEOUT;
+}
+
 /* fw_lock could be moved to 'struct firmware_priv' but since it is just
  * guarding for corner cases a global lock should be OK */
 static DEFINE_MUTEX(fw_lock);
@@ -541,31 +546,22 @@ static void _request_firmware_cleanup(const struct firmware **firmware_p)
 
 static int _request_firmware(const struct firmware *firmware,
 			     const char *name, struct device *device,
-			     bool uevent, bool nowait)
+			     bool uevent, bool nowait, long timeout)
 {
 	struct firmware_priv *fw_priv;
-	int retval;
-
-	retval = usermodehelper_read_trylock();
-	if (WARN_ON(retval)) {
-		dev_err(device, "firmware: %s will not be loaded\n", name);
-		return retval;
-	}
+	int retval = 0;
 
 	if (uevent)
 		dev_dbg(device, "firmware: requesting %s\n", name);
 
 	fw_priv = fw_create_instance(firmware, name, device, uevent, nowait);
-	if (IS_ERR(fw_priv)) {
-		retval = PTR_ERR(fw_priv);
-		goto out;
-	}
+	if (IS_ERR(fw_priv))
+		return PTR_ERR(fw_priv);
 
 	if (uevent) {
-		if (loading_timeout > 0)
+		if (timeout != MAX_SCHEDULE_TIMEOUT)
 			mod_timer(&fw_priv->timeout,
-				  round_jiffies_up(jiffies +
-						   loading_timeout * HZ));
+				  round_jiffies_up(jiffies + timeout));
 
 		kobject_uevent(&fw_priv->dev.kobj, KOBJ_ADD);
 	}
@@ -582,9 +578,6 @@ static int _request_firmware(const struct firmware *firmware,
 	mutex_unlock(&fw_lock);
 
 	fw_destroy_instance(fw_priv);
-
-out:
-	usermodehelper_read_unlock();
 	return retval;
 }
 
@@ -613,7 +606,14 @@ request_firmware(const struct firmware **firmware_p, const char *name,
 	if (ret <= 0)
 		return ret;
 
-	ret = _request_firmware(*firmware_p, name, device, true, false);
+	ret = usermodehelper_read_trylock();
+	if (WARN_ON(ret)) {
+		dev_err(device, "firmware: %s will not be loaded\n", name);
+	} else {
+		ret = _request_firmware(*firmware_p, name, device, true, false,
+					firmware_loading_timeout());
+		usermodehelper_read_unlock();
+	}
 	if (ret)
 		_request_firmware_cleanup(firmware_p);
 
@@ -648,6 +648,7 @@ static int request_firmware_work_func(void *arg)
 {
 	struct firmware_work *fw_work = arg;
 	const struct firmware *fw;
+	long timeout;
 	int ret;
 
 	if (!arg) {
@@ -659,8 +660,16 @@ static int request_firmware_work_func(void *arg)
 	if (ret <= 0)
 		goto out;
 
-	ret = _request_firmware(fw, fw_work->name, fw_work->device,
-				fw_work->uevent, true);
+	timeout = usermodehelper_read_lock_wait(firmware_loading_timeout());
+	if (timeout) {
+		ret = _request_firmware(fw, fw_work->name, fw_work->device,
+					fw_work->uevent, true, timeout);
+		usermodehelper_read_unlock();
+	} else {
+		dev_dbg(fw_work->device, "firmware: %s loading timed out\n",
+			fw_work->name);
+		ret = -EAGAIN;
+	}
 	if (ret)
 		_request_firmware_cleanup(&fw);
 
diff --git a/include/linux/kmod.h b/include/linux/kmod.h
index b25e2b80c059..ce9d9a13d777 100644
--- a/include/linux/kmod.h
+++ b/include/linux/kmod.h
@@ -117,6 +117,7 @@ extern void usermodehelper_init(void);
 extern int usermodehelper_disable(void);
 extern void usermodehelper_enable(void);
 extern int usermodehelper_read_trylock(void);
+extern long usermodehelper_read_lock_wait(long timeout);
 extern void usermodehelper_read_unlock(void);
 
 #endif /* __LINUX_KMOD_H__ */
diff --git a/kernel/kmod.c b/kernel/kmod.c
index 3973cde0cabf..75f76b66da6d 100644
--- a/kernel/kmod.c
+++ b/kernel/kmod.c
@@ -291,6 +291,12 @@ static atomic_t running_helpers = ATOMIC_INIT(0);
 static DECLARE_WAIT_QUEUE_HEAD(running_helpers_waitq);
 
 /*
+ * Used by usermodehelper_read_lock_wait() to wait for usermodehelper_disabled
+ * to become 'false'.
+ */
+static DECLARE_WAIT_QUEUE_HEAD(usermodehelper_disabled_waitq);
+
+/*
  * Time to wait for running_helpers to become zero before the setting of
  * usermodehelper_disabled in usermodehelper_disable() fails
  */
@@ -309,6 +315,33 @@ int usermodehelper_read_trylock(void)
 }
 EXPORT_SYMBOL_GPL(usermodehelper_read_trylock);
 
+long usermodehelper_read_lock_wait(long timeout)
+{
+	DEFINE_WAIT(wait);
+
+	if (timeout < 0)
+		return -EINVAL;
+
+	down_read(&umhelper_sem);
+	for (;;) {
+		prepare_to_wait(&usermodehelper_disabled_waitq, &wait,
+				TASK_UNINTERRUPTIBLE);
+		if (!usermodehelper_disabled)
+			break;
+
+		up_read(&umhelper_sem);
+
+		timeout = schedule_timeout(timeout);
+		if (!timeout)
+			break;
+
+		down_read(&umhelper_sem);
+	}
+	finish_wait(&usermodehelper_disabled_waitq, &wait);
+	return timeout;
+}
+EXPORT_SYMBOL_GPL(usermodehelper_read_lock_wait);
+
 void usermodehelper_read_unlock(void)
 {
 	up_read(&umhelper_sem);
@@ -316,6 +349,17 @@ void usermodehelper_read_unlock(void)
 EXPORT_SYMBOL_GPL(usermodehelper_read_unlock);
 
 /**
+ * usermodehelper_enable - allow new helpers to be started again
+ */
+void usermodehelper_enable(void)
+{
+	down_write(&umhelper_sem);
+	usermodehelper_disabled = 0;
+	wake_up(&usermodehelper_disabled_waitq);
+	up_write(&umhelper_sem);
+}
+
+/**
  * usermodehelper_disable - prevent new helpers from being started
  */
 int usermodehelper_disable(void)
@@ -338,22 +382,10 @@ int usermodehelper_disable(void)
 	if (retval)
 		return 0;
 
-	down_write(&umhelper_sem);
-	usermodehelper_disabled = 0;
-	up_write(&umhelper_sem);
+	usermodehelper_enable();
 	return -EAGAIN;
 }
 
-/**
- * usermodehelper_enable - allow new helpers to be started again
- */
-void usermodehelper_enable(void)
-{
-	down_write(&umhelper_sem);
-	usermodehelper_disabled = 0;
-	up_write(&umhelper_sem);
-}
-
 static void helper_lock(void)
 {
 	atomic_inc(&running_helpers);