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@redhat.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 8 insertions, 4 deletions

diff --git a/arch/powerpc/kernel/vio.c b/arch/powerpc/kernel/vio.c
index 536016d792ba..2d845d8199fc 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);
 }