[PATCH v4 net-next 01/10] net/ncsi: Disable HWA mode when no channels are found

[Gavin Shan]

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 <gws...@linux.vnet.ibm.com>
---
 net/ncsi/ncsi-manage.c | 12 ++++++++++--
 1 file changed, 10 insertions(+), 2 deletions(-)

diff --git a/net/ncsi/ncsi-manage.c b/net/ncsi/ncsi-manage.c
index a3bd5fa..5073e15 100644
--- a/net/ncsi/ncsi-manage.c
+++ b/net/ncsi/ncsi-manage.c
@@ -839,12 +839,15 @@ 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) !=
@@ -855,8 +858,13 @@ 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)
-- 
2.7.4