1 files changed, 80 insertions, 45 deletions

diff --git a/drivers/spi/spi-rspi.c b/drivers/spi/spi-rspi.c
index 10112745bb17..ad87a98f8f68 100644
--- a/drivers/spi/spi-rspi.c
+++ b/drivers/spi/spi-rspi.c
@@ -472,25 +472,52 @@ static int rspi_dma_transfer(struct rspi_data *rspi, struct sg_table *tx,
 	dma_cookie_t cookie;
 	int ret;
 
-	if (tx) {
-		desc_tx = dmaengine_prep_slave_sg(rspi->master->dma_tx,
-					tx->sgl, tx->nents, DMA_TO_DEVICE,
-					DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
-		if (!desc_tx)
-			return -EIO;
-
-		irq_mask |= SPCR_SPTIE;
-	}
+	/* First prepare and submit the DMA request(s), as this may fail */
 	if (rx) {
 		desc_rx = dmaengine_prep_slave_sg(rspi->master->dma_rx,
 					rx->sgl, rx->nents, DMA_FROM_DEVICE,
 					DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
-		if (!desc_rx)
-			return -EIO;
+		if (!desc_rx) {
+			ret = -EAGAIN;
+			goto no_dma_rx;
+		}
+
+		desc_rx->callback = rspi_dma_complete;
+		desc_rx->callback_param = rspi;
+		cookie = dmaengine_submit(desc_rx);
+		if (dma_submit_error(cookie)) {
+			ret = cookie;
+			goto no_dma_rx;
+		}
 
 		irq_mask |= SPCR_SPRIE;
 	}
 
+	if (tx) {
+		desc_tx = dmaengine_prep_slave_sg(rspi->master->dma_tx,
+					tx->sgl, tx->nents, DMA_TO_DEVICE,
+					DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
+		if (!desc_tx) {
+			ret = -EAGAIN;
+			goto no_dma_tx;
+		}
+
+		if (rx) {
+			/* No callback */
+			desc_tx->callback = NULL;
+		} else {
+			desc_tx->callback = rspi_dma_complete;
+			desc_tx->callback_param = rspi;
+		}
+		cookie = dmaengine_submit(desc_tx);
+		if (dma_submit_error(cookie)) {
+			ret = cookie;
+			goto no_dma_tx;
+		}
+
+		irq_mask |= SPCR_SPTIE;
+	}
+
 	/*
 	 * DMAC needs SPxIE, but if SPxIE is set, the IRQ routine will be
 	 * called. So, this driver disables the IRQ while DMA transfer.
@@ -503,34 +530,24 @@ static int rspi_dma_transfer(struct rspi_data *rspi, struct sg_table *tx,
 	rspi_enable_irq(rspi, irq_mask);
 	rspi->dma_callbacked = 0;
 
-	if (rx) {
-		desc_rx->callback = rspi_dma_complete;
-		desc_rx->callback_param = rspi;
-		cookie = dmaengine_submit(desc_rx);
-		if (dma_submit_error(cookie))
-			return cookie;
+	/* Now start DMA */
+	if (rx)
 		dma_async_issue_pending(rspi->master->dma_rx);
-	}
-	if (tx) {
-		if (rx) {
-			/* No callback */
-			desc_tx->callback = NULL;
-		} else {
-			desc_tx->callback = rspi_dma_complete;
-			desc_tx->callback_param = rspi;
-		}
-		cookie = dmaengine_submit(desc_tx);
-		if (dma_submit_error(cookie))
-			return cookie;
+	if (tx)
 		dma_async_issue_pending(rspi->master->dma_tx);
-	}
 
 	ret = wait_event_interruptible_timeout(rspi->wait,
 					       rspi->dma_callbacked, HZ);
 	if (ret > 0 && rspi->dma_callbacked)
 		ret = 0;
-	else if (!ret)
+	else if (!ret) {
+		dev_err(&rspi->master->dev, "DMA timeout\n");
 		ret = -ETIMEDOUT;
+		if (tx)
+			dmaengine_terminate_all(rspi->master->dma_tx);
+		if (rx)
+			dmaengine_terminate_all(rspi->master->dma_rx);
+	}
 
 	rspi_disable_irq(rspi, irq_mask);
 
@@ -540,6 +557,17 @@ static int rspi_dma_transfer(struct rspi_data *rspi, struct sg_table *tx,
 		enable_irq(rspi->rx_irq);
 
 	return ret;
+
+no_dma_tx:
+	if (rx)
+		dmaengine_terminate_all(rspi->master->dma_rx);
+no_dma_rx:
+	if (ret == -EAGAIN) {
+		pr_warn_once("%s %s: DMA not available, falling back to PIO\n",
+			     dev_driver_string(&rspi->master->dev),
+			     dev_name(&rspi->master->dev));
+	}
+	return ret;
 }
 
 static void rspi_receive_init(const struct rspi_data *rspi)
@@ -593,8 +621,10 @@ static int rspi_common_transfer(struct rspi_data *rspi,
 
 	if (rspi->master->can_dma && __rspi_can_dma(rspi, xfer)) {
 		/* rx_buf can be NULL on RSPI on SH in TX-only Mode */
-		return rspi_dma_transfer(rspi, &xfer->tx_sg,
-					 xfer->rx_buf ? &xfer->rx_sg : NULL);
+		ret = rspi_dma_transfer(rspi, &xfer->tx_sg,
+					xfer->rx_buf ? &xfer->rx_sg : NULL);
+		if (ret != -EAGAIN)
+			return ret;
 	}
 
 	ret = rspi_pio_transfer(rspi, xfer->tx_buf, xfer->rx_buf, xfer->len);
@@ -630,7 +660,6 @@ static int rspi_rz_transfer_one(struct spi_master *master,
 				struct spi_transfer *xfer)
 {
 	struct rspi_data *rspi = spi_master_get_devdata(master);
-	int ret;
 
 	rspi_rz_receive_init(rspi);
 
@@ -649,8 +678,11 @@ static int qspi_transfer_out(struct rspi_data *rspi, struct spi_transfer *xfer)
 {
 	int ret;
 
-	if (rspi->master->can_dma && __rspi_can_dma(rspi, xfer))
-		return rspi_dma_transfer(rspi, &xfer->tx_sg, NULL);
+	if (rspi->master->can_dma && __rspi_can_dma(rspi, xfer)) {
+		ret = rspi_dma_transfer(rspi, &xfer->tx_sg, NULL);
+		if (ret != -EAGAIN)
+			return ret;
+	}
 
 	ret = rspi_pio_transfer(rspi, xfer->tx_buf, NULL, xfer->len);
 	if (ret < 0)
@@ -664,8 +696,11 @@ static int qspi_transfer_out(struct rspi_data *rspi, struct spi_transfer *xfer)
 
 static int qspi_transfer_in(struct rspi_data *rspi, struct spi_transfer *xfer)
 {
-	if (rspi->master->can_dma && __rspi_can_dma(rspi, xfer))
-		return rspi_dma_transfer(rspi, NULL, &xfer->rx_sg);
+	if (rspi->master->can_dma && __rspi_can_dma(rspi, xfer)) {
+		int ret = rspi_dma_transfer(rspi, NULL, &xfer->rx_sg);
+		if (ret != -EAGAIN)
+			return ret;
+	}
 
 	return rspi_pio_transfer(rspi, NULL, xfer->rx_buf, xfer->len);
 }
@@ -927,19 +962,19 @@ static int rspi_request_dma(struct device *dev, struct spi_master *master,
 	return 0;
 }
 
-static void rspi_release_dma(struct rspi_data *rspi)
+static void rspi_release_dma(struct spi_master *master)
 {
-	if (rspi->master->dma_tx)
-		dma_release_channel(rspi->master->dma_tx);
-	if (rspi->master->dma_rx)
-		dma_release_channel(rspi->master->dma_rx);
+	if (master->dma_tx)
+		dma_release_channel(master->dma_tx);
+	if (master->dma_rx)
+		dma_release_channel(master->dma_rx);
 }
 
 static int rspi_remove(struct platform_device *pdev)
 {
 	struct rspi_data *rspi = platform_get_drvdata(pdev);
 
-	rspi_release_dma(rspi);
+	rspi_release_dma(rspi->master);
 	pm_runtime_disable(&pdev->dev);
 
 	return 0;
@@ -1141,7 +1176,7 @@ static int rspi_probe(struct platform_device *pdev)
 	return 0;
 
 error3:
-	rspi_release_dma(rspi);
+	rspi_release_dma(master);
 error2:
 	pm_runtime_disable(&pdev->dev);
 error1: