sparc64: ldc_connect() should not return EINVAL when handshake is in progress.

[ Upstream commit 4ec1b010 ]

The LDC handshake could have been asynchronously triggered
after ldc_bind() enables the ldc_rx() receive interrupt-handler
(and thus intercepts incoming control packets)
and before vio_port_up() calls ldc_connect(). If that is the case,
ldc_connect() should return 0 and let the state-machine
progress.
Signed-off-by: Sowmini Varadhan <sowmini.varadhan@oracle.com>
Acked-by: Karl Volz <karl.volz@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

arch/sparc/kernel/ldc.c

@@ -1339,7 +1339,7 @@ int ldc_connect(struct ldc_channel *lp)
 	if (!(lp->flags & LDC_FLAG_ALLOCED_QUEUES) ||
 	    !(lp->flags & LDC_FLAG_REGISTERED_QUEUES) ||
 	    lp->hs_state != LDC_HS_OPEN)
-		err = -EINVAL;
+		err = ((lp->hs_state > LDC_HS_OPEN) ? 0 : -EINVAL);
 	else
 		err = start_handshake(lp);