net/ncsi: wait for the last response to Deselect Package before configuring channel

The NCSI state machine as it's currently implemented assumes that
transition to the next logical state is performed either explicitly by
calling `schedule_work(&ndp->work)` to re-queue itself or implicitly
after processing the predefined (ndp->pending_req_num) number of
replies. Thus to avoid the configuration FSM from advancing prematurely
and getting out of sync with the process it's essential to not skip
waiting for a reply.

This patch makes the code wait for reception of the Deselect Package
response for the last package probed before proceeding to channel
configuration.

Thanks go to Potin Lai and Cosmo Chou for the initial investigation and
testing.

Fixes: 8e13f70be05e ("net/ncsi: Probe single packages to avoid conflict")
Cc: stable@vger.kernel.org
Signed-off-by: Paul Fertser <fercerpav@gmail.com>
Link: https://patch.msgid.link/20250116152900.8656-1-fercerpav@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

diff --git a/net/ncsi/ncsi-manage.c b/net/ncsi/ncsi-manage.c
index bf276eaf93307511ce36d026a02ded6db32a4f88..7891a537bddd11f3f98d88459748d0e29e26d9b0 100644 (file)
--- a/net/ncsi/ncsi-manage.c
+++ b/net/ncsi/ncsi-manage.c
@@ -1385,6 +1385,12 @@ static void ncsi_probe_channel(struct ncsi_dev_priv *ndp)
                nd->state = ncsi_dev_state_probe_package;
                break;
        case ncsi_dev_state_probe_package:
+               if (ndp->package_probe_id >= 8) {
+                       /* Last package probed, finishing */
+                       ndp->flags |= NCSI_DEV_PROBED;
+                       break;
+               }
+
                ndp->pending_req_num = 1;
 
                nca.type = NCSI_PKT_CMD_SP;
@@ -1501,13 +1507,8 @@ static void ncsi_probe_channel(struct ncsi_dev_priv *ndp)
                if (ret)
                        goto error;
 
-               /* Probe next package */
+               /* Probe next package after receiving response */
                ndp->package_probe_id++;
-               if (ndp->package_probe_id >= 8) {
-                       /* Probe finished */
-                       ndp->flags |= NCSI_DEV_PROBED;
-                       break;
-               }
                nd->state = ncsi_dev_state_probe_package;
                ndp->active_package = NULL;
                break;