From: Serge Semin <Sergey.Semin@baikalelectronics.ru>
To: Mark Brown <broonie@kernel.org>
Cc: Serge Semin <Sergey.Semin@baikalelectronics.ru>,
Serge Semin <fancer.lancer@gmail.com>,
Alexey Malahov <Alexey.Malahov@baikalelectronics.ru>,
Georgy Vlasov <Georgy.Vlasov@baikalelectronics.ru>,
Ramil Zaripov <Ramil.Zaripov@baikalelectronics.ru>,
Pavel Parkhomenko <Pavel.Parkhomenko@baikalelectronics.ru>,
Peter Ujfalusi <peter.ujfalusi@ti.com>,
Andy Shevchenko <andy.shevchenko@gmail.com>,
Andy Shevchenko <andriy.shevchenko@linux.intel.com>,
Feng Tang <feng.tang@intel.com>, Vinod Koul <vkoul@kernel.org>,
<linux-spi@vger.kernel.org>, <linux-kernel@vger.kernel.org>
Subject: [PATCH v2 02/11] spi: dw-dma: Fail DMA-based transfer if no Tx-buffer specified
Date: Sun, 20 Sep 2020 14:23:13 +0300 [thread overview]
Message-ID: <20200920112322.24585-3-Sergey.Semin@baikalelectronics.ru> (raw)
In-Reply-To: <20200920112322.24585-1-Sergey.Semin@baikalelectronics.ru>
Since commit 46164fde6b78 ("spi: dw: Fix Rx-only DMA transfers") if DMA
interface is enabled, then Tx-buffer must be available in each SPI
transfer. It's required since in order to activate the incoming data
reception either DMA or CPU must be pushing data out to the SPI bus.
But the DW APB SSI DMA driver code is still left in state as if Tx-buffer
might be optional, which is no longer true. Let's fix it so an error would
be returned if no Tx-buffer detected and DMA Tx would be always
enabled.
Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
---
drivers/spi/spi-dw-dma.c | 27 +++++++++++++--------------
1 file changed, 13 insertions(+), 14 deletions(-)
diff --git a/drivers/spi/spi-dw-dma.c b/drivers/spi/spi-dw-dma.c
index a7ff1e357f8b..1b013ac94a3f 100644
--- a/drivers/spi/spi-dw-dma.c
+++ b/drivers/spi/spi-dw-dma.c
@@ -262,9 +262,6 @@ dw_spi_dma_prepare_tx(struct dw_spi *dws, struct spi_transfer *xfer)
struct dma_slave_config txconf;
struct dma_async_tx_descriptor *txdesc;
- if (!xfer->tx_buf)
- return NULL;
-
memset(&txconf, 0, sizeof(txconf));
txconf.direction = DMA_MEM_TO_DEV;
txconf.dst_addr = dws->dma_addr;
@@ -383,17 +380,19 @@ static struct dma_async_tx_descriptor *dw_spi_dma_prepare_rx(struct dw_spi *dws,
static int dw_spi_dma_setup(struct dw_spi *dws, struct spi_transfer *xfer)
{
- u16 imr = 0, dma_ctrl = 0;
+ u16 imr, dma_ctrl;
- if (xfer->tx_buf)
- dma_ctrl |= SPI_DMA_TDMAE;
+ if (!xfer->tx_buf)
+ return -EINVAL;
+
+ /* Set the DMA handshaking interface */
+ dma_ctrl = SPI_DMA_TDMAE;
if (xfer->rx_buf)
dma_ctrl |= SPI_DMA_RDMAE;
dw_writel(dws, DW_SPI_DMACR, dma_ctrl);
/* Set the interrupt mask */
- if (xfer->tx_buf)
- imr |= SPI_INT_TXOI;
+ imr = SPI_INT_TXOI;
if (xfer->rx_buf)
imr |= SPI_INT_RXUI | SPI_INT_RXOI;
spi_umask_intr(dws, imr);
@@ -412,6 +411,8 @@ static int dw_spi_dma_transfer(struct dw_spi *dws, struct spi_transfer *xfer)
/* Prepare the TX dma transfer */
txdesc = dw_spi_dma_prepare_tx(dws, xfer);
+ if (!txdesc)
+ return -EINVAL;
/* Prepare the RX dma transfer */
rxdesc = dw_spi_dma_prepare_rx(dws, xfer);
@@ -423,17 +424,15 @@ static int dw_spi_dma_transfer(struct dw_spi *dws, struct spi_transfer *xfer)
dma_async_issue_pending(dws->rxchan);
}
- if (txdesc) {
- set_bit(TX_BUSY, &dws->dma_chan_busy);
- dmaengine_submit(txdesc);
- dma_async_issue_pending(dws->txchan);
- }
+ set_bit(TX_BUSY, &dws->dma_chan_busy);
+ dmaengine_submit(txdesc);
+ dma_async_issue_pending(dws->txchan);
ret = dw_spi_dma_wait(dws, xfer);
if (ret)
return ret;
- if (txdesc && dws->master->cur_msg->status == -EINPROGRESS) {
+ if (dws->master->cur_msg->status == -EINPROGRESS) {
ret = dw_spi_dma_wait_tx_done(dws, xfer);
if (ret)
return ret;
--
2.27.0
next prev parent reply other threads:[~2020-09-20 11:23 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-09-20 11:23 [PATCH v2 00/11] spi: dw-dma: Add max SG entries burst capability support Serge Semin
2020-09-20 11:23 ` [PATCH v2 01/11] spi: dw-dma: Set DMA Level registers on init Serge Semin
2020-09-20 11:23 ` Serge Semin [this message]
2020-09-20 11:23 ` [PATCH v2 03/11] spi: dw-dma: Configure the DMA channels in dma_setup Serge Semin
2020-09-20 11:23 ` [PATCH v2 04/11] spi: dw-dma: Check rx_buf availability in the xfer method Serge Semin
2020-09-20 11:23 ` [PATCH v2 05/11] spi: dw-dma: Move DMA transfers submission to the channels prep methods Serge Semin
2020-09-20 11:23 ` [PATCH v2 06/11] spi: dw-dma: Check DMA Tx-desc submission status Serge Semin
2020-09-20 11:23 ` [PATCH v2 07/11] spi: dw-dma: Remove DMA Tx-desc passing around Serge Semin
2020-09-20 11:23 ` [PATCH v2 08/11] spi: dw-dma: Detach DMA transfer into a dedicated method Serge Semin
2020-09-20 11:23 ` [PATCH v2 09/11] spi: dw-dma: Move DMAC register cleanup to DMA transfer method Serge Semin
2020-09-20 11:23 ` [PATCH v2 10/11] spi: dw-dma: Pass exact data to the DMA submit and wait methods Serge Semin
2020-09-20 11:23 ` [PATCH v2 11/11] spi: dw-dma: Add one-by-one SG list entries transfer Serge Semin
2020-09-29 16:23 ` [PATCH v2 00/11] spi: dw-dma: Add max SG entries burst capability support Mark Brown
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