[PATCH 3.2 017/185] powerpc/vio: Fix modalias_show return values

Ben Hutchings
2013-12-29T02:54:59Z

From: Prarit Bhargava <prarit@redhat.com>

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: Ben Hutchings <ben@decadent.org.uk>
---
arch/powerpc/kernel/vio.c | 12 ++++++++----
1 file changed, 8 insertions(+), 4 deletions(-)

--- a/arch/powerpc/kernel/vio.c
+++ b/arch/powerpc/kernel/vio.c
@@ -1351,11 +1351,15 @@ static ssize_t modalias_show(struct devi
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);
}