[3.13.y.z extended stable] Patch "iio: of_iio_channel_get_by_name() returns non-null pointers for error legs" has been added to staging queue

[Kamal Mostafa]

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

    iio: of_iio_channel_get_by_name() returns non-null pointers for error legs

to the linux-3.13.y-queue branch of the 3.13.y.z extended stable tree 
which can be found at:

 http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.13.y-queue

This patch is scheduled to be released in version 3.13.11.6.

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

For more information about the 3.13.y.z tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Kamal

------

>From 62cce1c7e437ae7d5277aade8197d5086945b215 Mon Sep 17 00:00:00 2001
From: Adam Thomson <Adam.Thomson.Opensource at diasemi.com>
Date: Thu, 6 Nov 2014 12:11:00 +0000
Subject: iio: of_iio_channel_get_by_name() returns non-null pointers for error
 legs

commit a2c12493ed7e63a18cef33a71686d12ffcd6600e upstream.

Currently in the inkern.c code for IIO framework, the function
of_iio_channel_get_by_name() will return a non-NULL pointer when
it cannot find a channel using of_iio_channel_get() and when it
tries to search for 'io-channel-ranges' property and fails. This
is incorrect behaviour as the function which calls this expects
a NULL pointer for failure. This patch rectifies the issue.

Signed-off-by: Adam Thomson <Adam.Thomson.Opensource at diasemi.com>
Signed-off-by: Jonathan Cameron <jic23 at kernel.org>
Signed-off-by: Kamal Mostafa <kamal at canonical.com>
---
 drivers/iio/inkern.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/iio/inkern.c b/drivers/iio/inkern.c
index 0cf5f8e..1e8e94d 100644
--- a/drivers/iio/inkern.c
+++ b/drivers/iio/inkern.c
@@ -183,7 +183,7 @@ static struct iio_channel *of_iio_channel_get_by_name(struct device_node *np,
 		else if (name && index >= 0) {
 			pr_err("ERROR: could not get IIO channel %s:%s(%i)\n",
 				np->full_name, name ? name : "", index);
-			return chan;
+			return NULL;
 		}

 		/*
@@ -193,8 +193,9 @@ static struct iio_channel *of_iio_channel_get_by_name(struct device_node *np,
 		 */
 		np = np->parent;
 		if (np && !of_get_property(np, "io-channel-ranges", NULL))
-			break;
+			return NULL;
 	}
+
 	return chan;
 }

@@ -317,6 +318,7 @@ struct iio_channel *iio_channel_get(struct device *dev,
 		if (channel != NULL)
 			return channel;
 	}
+
 	return iio_channel_get_sys(name, channel_name);
 }
 EXPORT_SYMBOL_GPL(iio_channel_get);
--
1.9.1