iwlwifi: pcie: refrain from SCD accesses

Up till now we accessed SCD configuration only for initial
configuration and for enabling command queue.
For a000 generation the command queue is open by default
and firmware configures the rest. No driver SCD accesses
are expected. Make sure this is the case.

Signed-off-by: Sara Sharon <sara.sharon@intel.com>
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>

drivers/net/wireless/intel/iwlwifi/pcie/trans.c

@@ -1960,6 +1960,10 @@ void iwl_trans_pcie_log_scd_error(struct iwl_trans *trans, struct iwl_txq *txq)
 	IWL_ERR(trans, "Current SW read_ptr %d write_ptr %d\n",
 		txq->q.read_ptr, txq->q.write_ptr);
 
+	if (trans->cfg->use_tfh)
+		/* TODO: access new SCD registers and dump them */
+		return;
+
 	scd_sram_addr = trans_pcie->scd_base_addr +
 			SCD_TX_STTS_QUEUE_OFFSET(txq->q.id);
 	iwl_trans_read_mem_bytes(trans, scd_sram_addr, buf, sizeof(buf));

drivers/net/wireless/intel/iwlwifi/pcie/tx.c

@@ -703,6 +703,9 @@ void iwl_pcie_tx_start(struct iwl_trans *trans, u32 scd_base_addr)
 	memset(trans_pcie->queue_stopped, 0, sizeof(trans_pcie->queue_stopped));
 	memset(trans_pcie->queue_used, 0, sizeof(trans_pcie->queue_used));
 
+	if (trans->cfg->use_tfh)
+		return;
+
 	trans_pcie->scd_base_addr =
 		iwl_read_prph(trans, SCD_SRAM_BASE_ADDR);
 
@@ -970,11 +973,13 @@ int iwl_pcie_tx_init(struct iwl_trans *trans)
 		}
 	}
 
-	if (trans->cfg->use_tfh)
+	if (trans->cfg->use_tfh) {
 		iwl_write_direct32(trans, TFH_TRANSFER_MODE,
 				   TFH_TRANSFER_MAX_PENDING_REQ |
 				   TFH_CHUNK_SIZE_128 |
 				   TFH_CHUNK_SPLIT_MODE);
+		return 0;
+	}
 
 	iwl_set_bits_prph(trans, SCD_GP_CTRL, SCD_GP_CTRL_AUTO_ACTIVE_MODE);
 	if (trans->cfg->base_params->num_of_queues > 20)
@@ -1249,6 +1254,9 @@ void iwl_trans_pcie_txq_enable(struct iwl_trans *trans, int txq_id, u16 ssn,
 	if (test_and_set_bit(txq_id, trans_pcie->queue_used))
 		WARN_ONCE(1, "queue %d already used - expect issues", txq_id);
 
+	if (cfg && trans->cfg->use_tfh)
+		WARN_ONCE(1, "Expected no calls to SCD configuration");
+
 	txq->wd_timeout = msecs_to_jiffies(wdg_timeout);
 
 	if (cfg) {
@@ -1366,6 +1374,9 @@ void iwl_trans_pcie_txq_disable(struct iwl_trans *trans, int txq_id,
 		return;
 	}
 
+	if (configure_scd && trans->cfg->use_tfh)
+		WARN_ONCE(1, "Expected no calls to SCD configuration");
+
 	if (configure_scd) {
 		iwl_scd_txq_set_inactive(trans, txq_id);