net/ncsi: Disable HWA mode when no channels are found

When there are no NCSI channels probed, HWA (Hardware Arbitration)
mode is enabled. It's not correct because HWA depends on the fact:
NCSI channels exist and all of them support HWA mode. This disables
HWA when no channels are probed.

Signed-off-by: Gavin Shan <gwshan@linux.vnet.ibm.com>
Signed-off-by: Samuel Mendoza-Jonas <sam@mendozajonas.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/ncsi/ncsi-manage.c

@@ -1005,12 +1005,15 @@ static bool ncsi_check_hwa(struct ncsi_dev_priv *ndp)
 	struct ncsi_package *np;
 	struct ncsi_channel *nc;
 	unsigned int cap;
+	bool has_channel = false;
 
 	/* The hardware arbitration is disabled if any one channel
 	 * doesn't support explicitly.
 	 */
 	NCSI_FOR_EACH_PACKAGE(ndp, np) {
 		NCSI_FOR_EACH_CHANNEL(np, nc) {
+			has_channel = true;
+
 			cap = nc->caps[NCSI_CAP_GENERIC].cap;
 			if (!(cap & NCSI_CAP_GENERIC_HWA) ||
 			    (cap & NCSI_CAP_GENERIC_HWA_MASK) !=
@@ -1021,8 +1024,13 @@ static bool ncsi_check_hwa(struct ncsi_dev_priv *ndp)
 		}
 	}
 
-	ndp->flags |= NCSI_DEV_HWA;
-	return true;
+	if (has_channel) {
+		ndp->flags |= NCSI_DEV_HWA;
+		return true;
+	}
+
+	ndp->flags &= ~NCSI_DEV_HWA;
+	return false;
 }
 
 static int ncsi_enable_hwa(struct ncsi_dev_priv *ndp)