From c910e2e2da49036496a5b8b34425043675218d51 Mon Sep 17 00:00:00 2001
From: Simon Glass <sjg@chromium.org>
Date: Wed, 23 Jul 2014 06:55:15 -0600
Subject: dm: Avoid accessing uclasses before they are ready

Don't allow access to uclasses before they have been initialised.

Signed-off-by: Simon Glass <sjg@chromium.org>

diff --git a/doc/driver-model/README.txt b/doc/driver-model/README.txt
index 346cf08..672497d 100644
--- a/doc/driver-model/README.txt
+++ b/doc/driver-model/README.txt
@@ -95,7 +95,7 @@ are provided in test/dm. To run them, try:
 You should see something like this:
 
     <...U-Boot banner...>
-    Running 16 driver model tests
+    Running 17 driver model tests
     Test: dm_test_autobind
     Test: dm_test_autoprobe
     Test: dm_test_children
@@ -116,6 +116,7 @@ You should see something like this:
     Test: dm_test_pre_reloc
     Test: dm_test_remove
     Test: dm_test_uclass
+    Test: dm_test_uclass_before_ready
     Failures: 0
 
 
diff --git a/drivers/core/uclass.c b/drivers/core/uclass.c
index a27f3d5..61ca17e 100644
--- a/drivers/core/uclass.c
+++ b/drivers/core/uclass.c
@@ -23,6 +23,8 @@ struct uclass *uclass_find(enum uclass_id key)
 {
 	struct uclass *uc;
 
+	if (!gd->dm_root)
+		return NULL;
 	/*
 	 * TODO(sjg@chromium.org): Optimise this, perhaps moving the found
 	 * node to the start of the list, or creating a linear array mapping
diff --git a/test/dm/core.c b/test/dm/core.c
index 24e0b6b..b0cfb42 100644
--- a/test/dm/core.c
+++ b/test/dm/core.c
@@ -570,3 +570,17 @@ static int dm_test_pre_reloc(struct dm_test_state *dms)
 	return 0;
 }
 DM_TEST(dm_test_pre_reloc, 0);
+
+static int dm_test_uclass_before_ready(struct dm_test_state *dms)
+{
+	struct uclass *uc;
+
+	ut_assertok(uclass_get(UCLASS_TEST, &uc));
+
+	memset(gd, '\0', sizeof(*gd));
+	ut_asserteq_ptr(NULL, uclass_find(UCLASS_TEST));
+
+	return 0;
+}
+
+DM_TEST(dm_test_uclass_before_ready, 0);
-- 
cgit v0.10.2