[3.16.y-ckt stable] Patch "reset: sunxi: fix spinlock initialization" has been added to staging queue

[Luis Henriques]

This is a note to let you know that I have just added a patch titled

    reset: sunxi: fix spinlock initialization

to the linux-3.16.y-queue branch of the 3.16.y-ckt extended stable tree 
which can be found at:

 http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.16.y-queue

This patch is scheduled to be released in version 3.16.7-ckt5.

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.16.y-ckt tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Luis

------

>From e3c75d412b520318c62a348150f9f8965b128fc0 Mon Sep 17 00:00:00 2001
From: Tyler Baker <tyler.baker at linaro.org>
Date: Mon, 12 Jan 2015 07:54:46 -0800
Subject: reset: sunxi: fix spinlock initialization

commit 41544f9f38f19cb46dc9a8fa37c58677a0300899 upstream.

Call spin_lock_init() before the spinlocks are used, both in early init
and probe functions preventing a lockdep splat.

I have been observing lockdep complaining [1] during boot on my a80 optimus [2]
when CONFIG_PROVE_LOCKING has been enabled. This patch resolves the splat,
and has been tested on a few other sunxi platforms without issue.

[1] http://storage.kernelci.org/next/next-20150107/arm-multi_v7_defconfig+CONFIG_PROVE_LOCKING=y/lab-tbaker/boot-sun9i-a80-optimus.html
[2] http://kernelci.org/boot/?a80-optimus

Signed-off-by: Tyler Baker <tyler.baker at linaro.org>
Acked-by: Philipp Zabel <p.zabel at pengutronix.de>
Signed-off-by: Kevin Hilman <khilman at linaro.org>
Signed-off-by: Olof Johansson <olof at lixom.net>
Signed-off-by: Luis Henriques <luis.henriques at canonical.com>
---
 drivers/reset/reset-sunxi.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/reset/reset-sunxi.c b/drivers/reset/reset-sunxi.c
index a94e7a7820b4..51272b5d7552 100644
--- a/drivers/reset/reset-sunxi.c
+++ b/drivers/reset/reset-sunxi.c
@@ -102,6 +102,8 @@ static int sunxi_reset_init(struct device_node *np)
 		goto err_alloc;
 	}

+	spin_lock_init(&data->lock);
+
 	data->rcdev.owner = THIS_MODULE;
 	data->rcdev.nr_resets = size * 32;
 	data->rcdev.ops = &sunxi_reset_ops;
@@ -157,6 +159,8 @@ static int sunxi_reset_probe(struct platform_device *pdev)
 	if (IS_ERR(data->membase))
 		return PTR_ERR(data->membase);

+	spin_lock_init(&data->lock);
+
 	data->rcdev.owner = THIS_MODULE;
 	data->rcdev.nr_resets = resource_size(res) * 32;
 	data->rcdev.ops = &sunxi_reset_ops;
--
2.1.4