[PATCH 1/2] soc: fsl: qmc: Only set completion interrupt when needed

[Christophe Leroy]

When no post-completion processing is expected, don't waste time
handling useless interrupts.

Only set QMC_BD_[R/T]X_I and QMC_BD_[R/T]X_UB when a completion
function is passed in.

Signed-off-by: Christophe Leroy <christophe.leroy at csgroup.eu>
---
 drivers/soc/fsl/qe/qmc.c | 18 +++++++++++-------
 1 file changed, 11 insertions(+), 7 deletions(-)

diff --git a/drivers/soc/fsl/qe/qmc.c b/drivers/soc/fsl/qe/qmc.c
index 36c0ccc06151..0a704fd0b1a0 100644
--- a/drivers/soc/fsl/qe/qmc.c
+++ b/drivers/soc/fsl/qe/qmc.c
@@ -474,7 +474,9 @@ int qmc_chan_write_submit(struct qmc_chan *chan, dma_addr_t addr, size_t length,
 	xfer_desc->context = context;
 
 	/* Activate the descriptor */
-	ctrl |= (QMC_BD_TX_R | QMC_BD_TX_UB);
+	ctrl |= QMC_BD_TX_R;
+	if (complete)
+		ctrl |= QMC_BD_TX_I | QMC_BD_TX_UB;
 	wmb(); /* Be sure to flush the descriptor before control update */
 	qmc_write16(&bd->cbd_sc, ctrl);
 
@@ -586,7 +588,9 @@ int qmc_chan_read_submit(struct qmc_chan *chan, dma_addr_t addr, size_t length,
 		  QMC_BD_RX_AB | QMC_BD_RX_CR);
 
 	/* Activate the descriptor */
-	ctrl |= (QMC_BD_RX_E | QMC_BD_RX_UB);
+	ctrl |= QMC_BD_RX_E;
+	if (complete)
+		ctrl |= QMC_BD_RX_I | QMC_BD_RX_UB;
 	wmb(); /* Be sure to flush data before descriptor activation */
 	qmc_write16(&bd->cbd_sc, ctrl);
 
@@ -1482,19 +1486,19 @@ static int qmc_setup_chan(struct qmc *qmc, struct qmc_chan *chan)
 
 	/* Init Rx BDs and set Wrap bit on last descriptor */
 	BUILD_BUG_ON(QMC_NB_RXBDS == 0);
-	val = QMC_BD_RX_I;
 	for (i = 0; i < QMC_NB_RXBDS; i++) {
 		bd = chan->rxbds + i;
-		qmc_write16(&bd->cbd_sc, val);
+		qmc_write16(&bd->cbd_sc, 0);
 	}
 	bd = chan->rxbds + QMC_NB_RXBDS - 1;
-	qmc_write16(&bd->cbd_sc, val | QMC_BD_RX_W);
+	qmc_write16(&bd->cbd_sc, QMC_BD_RX_W);
 
 	/* Init Tx BDs and set Wrap bit on last descriptor */
 	BUILD_BUG_ON(QMC_NB_TXBDS == 0);
-	val = QMC_BD_TX_I;
 	if (chan->mode == QMC_HDLC)
-		val |= QMC_BD_TX_L | QMC_BD_TX_TC;
+		val = QMC_BD_TX_L | QMC_BD_TX_TC;
+	else
+		val = 0;
 	for (i = 0; i < QMC_NB_TXBDS; i++) {
 		bd = chan->txbds + i;
 		qmc_write16(&bd->cbd_sc, val);
-- 
2.47.0