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>

1 files changed, 10 insertions, 2 deletions

diff --git a/net/ncsi/ncsi-manage.c b/net/ncsi/ncsi-manage.c
index b022deb39d31..0966eff48ce7 100644
--- a/net/ncsi/ncsi-manage.c
+++ b/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)