iwlwifi: trans: configure the scheduler enable register

Currently the firmware is handling this, but that is wrong as it then
needs to assume a certain command queue, therefore this should be in
the driver; add it here so it can be removed from the firmware in the
future.

Signed-off-by: Avri Altman <avri.altman@intel.com>
Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>

drivers/net/wireless/iwlwifi/iwl-prph.h

@@ -281,6 +281,7 @@
 #define SCD_CHAINEXT_EN		(SCD_BASE + 0x244)
 #define SCD_AGGR_SEL		(SCD_BASE + 0x248)
 #define SCD_INTERRUPT_MASK	(SCD_BASE + 0x108)
+#define SCD_EN_CTRL		(SCD_BASE + 0x254)
 
 static inline unsigned int SCD_QUEUE_WRPTR(unsigned int chnl)
 {

drivers/net/wireless/iwlwifi/iwl-scd.h

@@ -109,4 +109,10 @@ static inline void iwl_scd_deactivate_fifos(struct iwl_trans *trans)
 {
 	iwl_write_prph(trans, SCD_TXFACT, 0);
 }
+
+static inline void iwl_scd_enable_set_active(struct iwl_trans *trans,
+					     u32 value)
+{
+	iwl_write_prph(trans, SCD_EN_CTRL, value);
+}
 #endif

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

@@ -1078,6 +1078,10 @@ void iwl_trans_pcie_txq_enable(struct iwl_trans *trans, int txq_id, u16 ssn,
 	if (cfg) {
 		fifo = cfg->fifo;
 
+		/* Disable the scheduler prior configuring the cmd queue */
+		if (txq_id == trans_pcie->cmd_queue)
+			iwl_scd_enable_set_active(trans, 0);
+
 		/* Stop this Tx queue before configuring it */
 		iwl_scd_txq_set_inactive(trans, txq_id);
 
@@ -1135,6 +1139,10 @@ void iwl_trans_pcie_txq_enable(struct iwl_trans *trans, int txq_id, u16 ssn,
 			       (cfg->fifo << SCD_QUEUE_STTS_REG_POS_TXF) |
 			       (1 << SCD_QUEUE_STTS_REG_POS_WSL) |
 			       SCD_QUEUE_STTS_REG_MSK);
+
+		/* enable the scheduler for this queue (only) */
+		if (txq_id == trans_pcie->cmd_queue)
+			iwl_scd_enable_set_active(trans, BIT(txq_id));
 	}
 
 	trans_pcie->txq[txq_id].active = true;