[ 3.8.y.z extended stable ] Patch "powerpc/vio: Fix modalias_show return values" has been added to staging queue

[Kamal Mostafa]

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

    powerpc/vio: Fix modalias_show return values

to the linux-3.8.y-queue branch of the 3.8.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-3.8.y-queue

This patch is scheduled to be released in version 3.8.13.11.

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

For more information about the 3.8.y.z tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Kamal

------

>From 992727f731e123c8992dfa54f5280c36eee72c5f Mon Sep 17 00:00:00 2001
From: Prarit Bhargava <prarit at redhat.com>
Date: Mon, 23 Sep 2013 09:33:36 -0400
Subject: powerpc/vio: Fix modalias_show return values

commit e82b89a6f19bae73fb064d1b3dd91fcefbb478f4 upstream.

modalias_show() should return an empty string on error, not -ENODEV.

This causes the following false and annoying error:

> find /sys/devices -name modalias -print0 | xargs -0 cat >/dev/null
cat: /sys/devices/vio/4000/modalias: No such device
cat: /sys/devices/vio/4001/modalias: No such device
cat: /sys/devices/vio/4002/modalias: No such device
cat: /sys/devices/vio/4004/modalias: No such device
cat: /sys/devices/vio/modalias: No such device

Signed-off-by: Prarit Bhargava <prarit at redhat.com>
Signed-off-by: Benjamin Herrenschmidt <benh at kernel.crashing.org>
Signed-off-by: Kamal Mostafa <kamal at canonical.com>
---
 arch/powerpc/kernel/vio.c | 12 ++++++++----
 1 file changed, 8 insertions(+), 4 deletions(-)

diff --git a/arch/powerpc/kernel/vio.c b/arch/powerpc/kernel/vio.c
index 536016d..2d845d8 100644
--- a/arch/powerpc/kernel/vio.c
+++ b/arch/powerpc/kernel/vio.c
@@ -1529,11 +1529,15 @@ static ssize_t modalias_show(struct device *dev, struct device_attribute *attr,
 	const char *cp;

 	dn = dev->of_node;
-	if (!dn)
-		return -ENODEV;
+	if (!dn) {
+		strcat(buf, "\n");
+		return strlen(buf);
+	}
 	cp = of_get_property(dn, "compatible", NULL);
-	if (!cp)
-		return -ENODEV;
+	if (!cp) {
+		strcat(buf, "\n");
+		return strlen(buf);
+	}

 	return sprintf(buf, "vio:T%sS%s\n", vio_dev->type, cp);
 }
--
1.8.1.2