patches.renesas/0021-base-soc-Early-register-bus-when-needed.patch

From 0c2851a91abbf4ea96e549c695f89aa2f57bba3d Mon Sep 17 00:00:00 2001
From: Geert Uytterhoeven <geert+renesas@glider.be>
Date: Tue, 27 Sep 2016 17:10:29 +0200
Subject: [PATCH 021/299] base: soc: Early register bus when needed

If soc_device_register() is called before soc_bus_register(), it crashes
with a NULL pointer dereference.

soc_bus_register() is already a core_initcall(), but drivers/base/ is
entered later than e.g. drivers/pinctrl/ and drivers/soc/. Hence there
are several subsystems that may need to know SoC revision information,
while it's not so easy to initialize the SoC bus even earlier using an
initcall.

To fix this, let soc_device_register() register the bus early if that
hasn't happened yet.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Acked-by: Arnd Bergmann <arnd@arndb.de>
(cherry picked from commit 1da1b3628df34a2a5e38b70c8551770aadce969d)
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>
---
 drivers/base/soc.c |    9 +++++++++
 1 file changed, 9 insertions(+)

--- a/drivers/base/soc.c
+++ b/drivers/base/soc.c
@@ -113,6 +113,12 @@ struct soc_device *soc_device_register(s
 	struct soc_device *soc_dev;
 	int ret;
 
+	if (!soc_bus_type.p) {
+		ret = bus_register(&soc_bus_type);
+		if (ret)
+			goto out1;
+	}
+
 	soc_dev = kzalloc(sizeof(*soc_dev), GFP_KERNEL);
 	if (!soc_dev) {
 		ret = -ENOMEM;
@@ -156,6 +162,9 @@ void soc_device_unregister(struct soc_de
 
 static int __init soc_bus_register(void)
 {
+	if (soc_bus_type.p)
+		return 0;
+
 	return bus_register(&soc_bus_type);
 }
 core_initcall(soc_bus_register);