ntb: ntb_test: ensure the link is up before trying to configure the mws

commit 0eb46345364d7318b11068c46e8a68d5dc10f65e upstream.

After the link tests, there is a race on one side of the test for
the link coming up. It's possible, in some cases, for the test script
to write to the 'peer_trans' files before the link has come up.

To fix this, we simply use the link event file to ensure both sides
see the link as up before continuning.

Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
Acked-by: Allen Hubbe <Allen.Hubbe@dell.com>
Signed-off-by: Jon Mason <jdmason@kudzu.us>
Fixes: a9c59ef77458 ("ntb_test: Add a selftest script for the NTB subsystem")
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/tools/testing/selftests/ntb/ntb_test.sh b/tools/testing/selftests/ntb/ntb_test.sh
index 13f5198..b3c48fc 100755 (executable)
--- a/tools/testing/selftests/ntb/ntb_test.sh
+++ b/tools/testing/selftests/ntb/ntb_test.sh
@@ -326,6 +326,10 @@ function ntb_tool_tests()
        link_test $LOCAL_TOOL $REMOTE_TOOL
        link_test $REMOTE_TOOL $LOCAL_TOOL
 
+       #Ensure the link is up on both sides before continuing
+       write_file Y $LOCAL_TOOL/link_event
+       write_file Y $REMOTE_TOOL/link_event
+
        for PEER_TRANS in $(ls $LOCAL_TOOL/peer_trans*); do
                PT=$(basename $PEER_TRANS)
                write_file $MW_SIZE $LOCAL_TOOL/$PT