Merge tag 'spi-v3.17-rc3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi

Pull spi bugfixes from Mark Brown:
 "A smattering of bug fixes for the SPI subsystem, all in driver code
  which has seen active work recently and none of them with any great
  global impact.

  There's also a new ACPI ID for the pxa2xx driver which required no
  code changes and the addition of kerneldoc for some structure fields
  that were missing it and generating warnings during documentation
  builds as a result"

* tag 'spi-v3.17-rc3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi:
  spi: sh-msiof: Fix transmit-only DMA transfers
  spi/rockchip: Avoid accidentally turning off the clock
  spi: dw: fix kernel crash due to NULL pointer dereference
  spi: dw-pci: fix bug when regs left uninitialized
  spi: davinci: fix SPI_NO_CS functionality
  spi/rockchip: fixup incorrect dma direction setting
  spi/pxa2xx: Add ACPI ID for Intel Braswell
  spi: spi-au1550: fix build failure
  spi: rspi: Fix leaking of unused DMA descriptors
  spi: sh-msiof: Fix leaking of unused DMA descriptors
  spi: Add missing kerneldoc bits
  spi/omap-mcspi: Fix the spi task hangs waiting dma_rx

1 files changed, 38 insertions, 33 deletions

diff --git a/drivers/spi/spi-sh-msiof.c b/drivers/spi/spi-sh-msiof.c
index 2a4354dcd661..543075b80f16 100644
--- a/drivers/spi/spi-sh-msiof.c
+++ b/drivers/spi/spi-sh-msiof.c
@@ -636,48 +636,38 @@ static int sh_msiof_dma_once(struct sh_msiof_spi_priv *p, const void *tx,
 	dma_cookie_t cookie;
 	int ret;
 
-	if (tx) {
-		ier_bits |= IER_TDREQE | IER_TDMAE;
-		dma_sync_single_for_device(p->master->dma_tx->device->dev,
-					   p->tx_dma_addr, len, DMA_TO_DEVICE);
-		desc_tx = dmaengine_prep_slave_single(p->master->dma_tx,
-					p->tx_dma_addr, len, DMA_TO_DEVICE,
-					DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
-		if (!desc_tx)
-			return -EAGAIN;
-	}
-
+	/* First prepare and submit the DMA request(s), as this may fail */
 	if (rx) {
 		ier_bits |= IER_RDREQE | IER_RDMAE;
 		desc_rx = dmaengine_prep_slave_single(p->master->dma_rx,
 					p->rx_dma_addr, len, DMA_FROM_DEVICE,
 					DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
-		if (!desc_rx)
-			return -EAGAIN;
-	}
-
-	/* 1 stage FIFO watermarks for DMA */
-	sh_msiof_write(p, FCTR, FCTR_TFWM_1 | FCTR_RFWM_1);
-
-	/* setup msiof transfer mode registers (32-bit words) */
-	sh_msiof_spi_set_mode_regs(p, tx, rx, 32, len / 4);
-
-	sh_msiof_write(p, IER, ier_bits);
-
-	reinit_completion(&p->done);
+		if (!desc_rx) {
+			ret = -EAGAIN;
+			goto no_dma_rx;
+		}
 
-	if (rx) {
 		desc_rx->callback = sh_msiof_dma_complete;
 		desc_rx->callback_param = p;
 		cookie = dmaengine_submit(desc_rx);
 		if (dma_submit_error(cookie)) {
 			ret = cookie;
-			goto stop_ier;
+			goto no_dma_rx;
 		}
-		dma_async_issue_pending(p->master->dma_rx);
 	}
 
 	if (tx) {
+		ier_bits |= IER_TDREQE | IER_TDMAE;
+		dma_sync_single_for_device(p->master->dma_tx->device->dev,
+					   p->tx_dma_addr, len, DMA_TO_DEVICE);
+		desc_tx = dmaengine_prep_slave_single(p->master->dma_tx,
+					p->tx_dma_addr, len, 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;
@@ -688,15 +678,30 @@ static int sh_msiof_dma_once(struct sh_msiof_spi_priv *p, const void *tx,
 		cookie = dmaengine_submit(desc_tx);
 		if (dma_submit_error(cookie)) {
 			ret = cookie;
-			goto stop_rx;
+			goto no_dma_tx;
 		}
-		dma_async_issue_pending(p->master->dma_tx);
 	}
 
+	/* 1 stage FIFO watermarks for DMA */
+	sh_msiof_write(p, FCTR, FCTR_TFWM_1 | FCTR_RFWM_1);
+
+	/* setup msiof transfer mode registers (32-bit words) */
+	sh_msiof_spi_set_mode_regs(p, tx, rx, 32, len / 4);
+
+	sh_msiof_write(p, IER, ier_bits);
+
+	reinit_completion(&p->done);
+
+	/* Now start DMA */
+	if (rx)
+		dma_async_issue_pending(p->master->dma_rx);
+	if (tx)
+		dma_async_issue_pending(p->master->dma_tx);
+
 	ret = sh_msiof_spi_start(p, rx);
 	if (ret) {
 		dev_err(&p->pdev->dev, "failed to start hardware\n");
-		goto stop_tx;
+		goto stop_dma;
 	}
 
 	/* wait for tx fifo to be emptied / rx fifo to be filled */
@@ -726,14 +731,14 @@ static int sh_msiof_dma_once(struct sh_msiof_spi_priv *p, const void *tx,
 stop_reset:
 	sh_msiof_reset_str(p);
 	sh_msiof_spi_stop(p, rx);
-stop_tx:
+stop_dma:
 	if (tx)
 		dmaengine_terminate_all(p->master->dma_tx);
-stop_rx:
+no_dma_tx:
 	if (rx)
 		dmaengine_terminate_all(p->master->dma_rx);
-stop_ier:
 	sh_msiof_write(p, IER, 0);
+no_dma_rx:
 	return ret;
 }