iwlwifi: mvm: loosen nssn comparison to reorder buffer head

[cascardo/linux.git] / drivers / net / wireless / intel / iwlwifi / mvm / rxmq.c

diff --git a/drivers/net/wireless/intel/iwlwifi/mvm/rxmq.c b/drivers/net/wireless/intel/iwlwifi/mvm/rxmq.c
index 5fe7a0e..ac2c571 100644 (file)
--- a/drivers/net/wireless/intel/iwlwifi/mvm/rxmq.c
+++ b/drivers/net/wireless/intel/iwlwifi/mvm/rxmq.c
@@ -395,6 +395,18 @@ int iwl_mvm_notify_rx_queue(struct iwl_mvm *mvm, u32 rxq_mask,
        return ret;
 }
 
+/*
+ * Returns true if sn2 - buffer_size < sn1 < sn2.
+ * To be used only in order to compare reorder buffer head with NSSN.
+ * We fully trust NSSN unless it is behind us due to reorder timeout.
+ * Reorder timeout can only bring us up to buffer_size SNs ahead of NSSN.
+ */
+static bool iwl_mvm_is_sn_less(u16 sn1, u16 sn2, u16 buffer_size)
+{
+       return ieee80211_sn_less(sn1, sn2) &&
+              !ieee80211_sn_less(sn1, sn2 - buffer_size);
+}
+
 #define RX_REORDER_BUF_TIMEOUT_MQ (HZ / 10)
 
 static void iwl_mvm_release_frames(struct iwl_mvm *mvm,
@@ -408,10 +420,10 @@ static void iwl_mvm_release_frames(struct iwl_mvm *mvm,
        lockdep_assert_held(&reorder_buf->lock);
 
        /* ignore nssn smaller than head sn - this can happen due to timeout */
-       if (ieee80211_sn_less(nssn, ssn))
+       if (iwl_mvm_is_sn_less(nssn, ssn, reorder_buf->buf_size))
                return;
 
-       while (ieee80211_sn_less(ssn, nssn)) {
+       while (iwl_mvm_is_sn_less(ssn, nssn, reorder_buf->buf_size)) {
                int index = ssn % reorder_buf->buf_size;
                struct sk_buff_head *skb_list = &reorder_buf->entries[index];
                struct sk_buff *skb;
@@ -625,7 +637,8 @@ static bool iwl_mvm_reorder(struct iwl_mvm *mvm,
         * rest of the function will take of storing it and releasing up to the
         * nssn
         */
-       if (!ieee80211_sn_less(nssn, buffer->head_sn + buffer->buf_size)) {
+       if (!iwl_mvm_is_sn_less(nssn, buffer->head_sn + buffer->buf_size,
+                               buffer->buf_size)) {
                u16 min_sn = ieee80211_sn_less(sn, nssn) ? sn : nssn;
 
                iwl_mvm_release_frames(mvm, sta, napi, buffer, min_sn);
@@ -637,7 +650,8 @@ static bool iwl_mvm_reorder(struct iwl_mvm *mvm,
 
        /* release immediately if allowed by nssn and no stored frames */
        if (!buffer->num_stored && ieee80211_sn_less(sn, nssn)) {
-               if (ieee80211_sn_less(buffer->head_sn, nssn))
+               if (iwl_mvm_is_sn_less(buffer->head_sn, nssn,
+                                      buffer->buf_size))
                        buffer->head_sn = nssn;
                /* No need to update AMSDU last SN - we are moving the head */
                spin_unlock_bh(&buffer->lock);