wifi: iwlwifi: mvm: avoid outdated reorder buffer head_sn

If no frames are received on a queue for a while, the reorder buffer
head_sn may be an old one. When the next frame that is received on
that queue and buffered is a subframe of an AMSDU but not the last
subframe, it will not update the buffer's head_sn. When the frame
release notification arrives, it will not release the buffered frame
because it will look like the notification's NSSN is lower than the
buffer's head_sn (because of a wraparound).
Fix it by updating the head_sn when the first frame is buffered.

Signed-off-by: Avraham Stern <avraham.stern@intel.com>
Reviewed-by: Daniel Gabay <daniel.gabay@intel.com>
Reviewed-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Miri Korenblit <miriam.rachel.korenblit@intel.com>
Link: https://patch.msgid.link/20250723094230.795ec0cb8817.I9ec9a3508e7935e8d1833ea3e086066fdefee644@changeid

diff --git a/drivers/net/wireless/intel/iwlwifi/mvm/rxmq.c b/drivers/net/wireless/intel/iwlwifi/mvm/rxmq.c
index 4b57ca56e1f695c7a8fc1c2167a9153c195b7553..62e76a79f621fbcf139ebbe7c3e56a1615526fab 100644 (file)
--- a/drivers/net/wireless/intel/iwlwifi/mvm/rxmq.c
+++ b/drivers/net/wireless/intel/iwlwifi/mvm/rxmq.c
@@ -905,10 +905,15 @@ static bool iwl_mvm_reorder(struct iwl_mvm *mvm,
         * already ahead and it will be dropped.
         * If the last sub-frame is not on this queue - we will get frame
         * release notification with up to date NSSN.
+        * If this is the first frame that is stored in the buffer, the head_sn
+        * may be outdated. Update it based on the last NSSN to make sure it
+        * will be released when the frame release notification arrives.
         */
        if (!amsdu || last_subframe)
                iwl_mvm_release_frames(mvm, sta, napi, baid_data,
                                       buffer, nssn);
+       else if (buffer->num_stored == 1)
+               buffer->head_sn = nssn;
 
        spin_unlock_bh(&buffer->lock);
        return true;