powerpc/vio: Fix modalias_show return values

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>
CC: <stable@vger.kernel.org>

diff --git a/arch/powerpc/kernel/vio.c b/arch/powerpc/kernel/vio.c
index 78a350670de32b4ba7013ea8fefe2ab5c0d5d626..d38cc08b16c7f23831e3af558bfe35908e14af47 100644 (file)
--- a/arch/powerpc/kernel/vio.c
+++ b/arch/powerpc/kernel/vio.c
@@ -1530,11 +1530,15 @@ 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);
 }