kni: update link only on change

'rte_kni_update_link()' updates virtual KNI interface link using kernel
sysfs interface.
If the requested link status is same as interface link status, do not
update the link status but return with success.

Signed-off-by: Ferruh Yigit <ferruh.yigit@intel.com>

diff --git a/lib/kni/rte_kni.c b/lib/kni/rte_kni.c
index eb24b0d..d3e2360 100644 (file)
--- a/lib/kni/rte_kni.c
+++ b/lib/kni/rte_kni.c
@@ -811,6 +811,9 @@ rte_kni_update_link(struct rte_kni *kni, unsigned int linkup)
        }
        old_linkup = (old_carrier[0] == '1');
 
+       if (old_linkup == (int)linkup)
+               goto out;
+
        new_carrier = linkup ? "1" : "0";
        ret = write(fd, new_carrier, 1);
        if (ret < 1) {
@@ -818,7 +821,7 @@ rte_kni_update_link(struct rte_kni *kni, unsigned int linkup)
                close(fd);
                return -1;
        }
-
+out:
        close(fd);
        return old_linkup;
 }

diff --git a/lib/kni/version.map b/lib/kni/version.map
index a93da95..bb810a7 100644 (file)
--- a/lib/kni/version.map
+++ b/lib/kni/version.map
@@ -19,5 +19,6 @@ DPDK_21 {
 EXPERIMENTAL {
        global:
 
+       # updated in v21.08
        rte_kni_update_link;
 };