[PATCH] spi: spi-fsl-dspi: Fix SPI transfer issue when using multiple SPI_IOC_MESSAGE

From: Sanchayan Maity
Date: Thu Nov 17 2016 - 07:16:48 EST


Current DMA implementation had a bug where the DMA transfer would
exit the loop in dspi_transfer_one_message after the completion of
a single transfer. This results in a multi message transfer submitted
with SPI_IOC_MESSAGE to terminate incorrectly without an error.

Signed-off-by: Sanchayan Maity <maitysanchayan@xxxxxxxxx>
Reviewed-by: Stefan Agner <stefan@xxxxxxxx>
Signed-off-by: Mark Brown <broonie@xxxxxxxxxx>
---
drivers/spi/spi-fsl-dspi.c | 12 ++++++++----
1 file changed, 8 insertions(+), 4 deletions(-)

diff --git a/drivers/spi/spi-fsl-dspi.c b/drivers/spi/spi-fsl-dspi.c
index bc64700b514d..b1ee1f521ba0 100644
--- a/drivers/spi/spi-fsl-dspi.c
+++ b/drivers/spi/spi-fsl-dspi.c
@@ -714,7 +714,7 @@ static int dspi_transfer_one_message(struct spi_master *master,
SPI_RSER_TFFFE | SPI_RSER_TFFFD |
SPI_RSER_RFDFE | SPI_RSER_RFDFD);
status = dspi_dma_xfer(dspi);
- goto out;
+ break;
default:
dev_err(&dspi->pdev->dev, "unsupported trans_mode %u\n",
trans_mode);
@@ -722,9 +722,13 @@ static int dspi_transfer_one_message(struct spi_master *master,
goto out;
}

- if (wait_event_interruptible(dspi->waitq, dspi->waitflags))
- dev_err(&dspi->pdev->dev, "wait transfer complete fail!\n");
- dspi->waitflags = 0;
+ if (trans_mode != DSPI_DMA_MODE) {
+ if (wait_event_interruptible(dspi->waitq,
+ dspi->waitflags))
+ dev_err(&dspi->pdev->dev,
+ "wait transfer complete fail!\n");
+ dspi->waitflags = 0;
+ }

if (transfer->delay_usecs)
udelay(transfer->delay_usecs);
--
2.10.2