ath10k: prevent some tx flushing failures

Firmware could request inspection of some
submitted tx requests. Since the callback wasn't
implemented it was possible to bleed tx msdu_ids
which could translate to tx flushing timeouts.

There's nothing ath10k can do to help firmware
with tx processing now so just report all tx
frames as already inspected to prevent firmware
from sending up inspection events and force it to
report regular tx completion indications with
discard status.
Signed-off-by: Michal Kazior <michal.kazior@tieto.com>
Signed-off-by: Kalle Valo <kvalo@qca.qualcomm.com>

drivers/net/wireless/ath/ath10k/htt_rx.c

@@ -1516,6 +1516,13 @@ void ath10k_htt_t2h_msg_handler(struct ath10k *ar, struct sk_buff *skb)
 		trace_ath10k_htt_stats(skb->data, skb->len);
 		break;
 	case HTT_T2H_MSG_TYPE_TX_INSPECT_IND:
+		/* Firmware can return tx frames if it's unable to fully
+		 * process them and suspects host may be able to fix it. ath10k
+		 * sends all tx frames as already inspected so this shouldn't
+		 * happen unless fw has a bug.
+		 */
+		ath10k_warn("received an unexpected htt tx inspect event\n");
+		break;
 	case HTT_T2H_MSG_TYPE_RX_ADDBA:
 	case HTT_T2H_MSG_TYPE_RX_DELBA:
 	case HTT_T2H_MSG_TYPE_RX_FLUSH:

drivers/net/wireless/ath/ath10k/htt_tx.c

@@ -531,6 +531,12 @@ int ath10k_htt_tx(struct ath10k_htt *htt, struct sk_buff *msdu)
 	flags1 |= HTT_DATA_TX_DESC_FLAGS1_CKSUM_L3_OFFLOAD;
 	flags1 |= HTT_DATA_TX_DESC_FLAGS1_CKSUM_L4_OFFLOAD;
 
+	/* Prevent firmware from sending up tx inspection requests. There's
+	 * nothing ath10k can do with frames requested for inspection so force
+	 * it to simply rely a regular tx completion with discard status.
+	 */
+	flags1 |= HTT_DATA_TX_DESC_FLAGS1_POSTPONED;
+
 	skb_cb->htt.txbuf->cmd_hdr.msg_type = HTT_H2T_MSG_TYPE_TX_FRM;
 	skb_cb->htt.txbuf->cmd_tx.flags0 = flags0;
 	skb_cb->htt.txbuf->cmd_tx.flags1 = __cpu_to_le16(flags1);