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

commit 6bb194d036c6e1b329dcdff459338cdd9a54802a upstream.

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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/net/ncsi/ncsi-manage.c b/net/ncsi/ncsi-manage.c
index bb3248214746a7a094cd4b22441e5f5a8eaf805d..c987c8e1c4d9c46da458f42ccb788294f80d90de 100644 (file)
--- a/net/ncsi/ncsi-manage.c
+++ b/net/ncsi/ncsi-manage.c
@@ -1345,6 +1345,12 @@ 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;
@@ -1461,13 +1467,8 @@ 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;