[PATCH] spi: spi-fsl-dspi: Fill actual_length when doing DMA transfer

[Andrey Smirnov]

Users of SPI device drivers may rely on 'actual_length', so it is
important that information is correctly reported. One example would be
spi_mem_exec_op() which will fail if 'actual_length' doesn't match
requested transfer length. To fix the problem, add necessary code to
populate 'actual_length'.

Cc: Mark Brown <broo...@kernel.org>
Cc: Sanchayan Maity <maitysancha...@gmail.com>
Cc: Stefan Agner <ste...@agner.ch>
Cc: cphe...@gmail.com
Cc: linux-...@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Andrey Smirnov <andrew.smir...@gmail.com>
---
 drivers/spi/spi-fsl-dspi.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/drivers/spi/spi-fsl-dspi.c b/drivers/spi/spi-fsl-dspi.c
index 0630962ce442..8877dd1e18dc 100644
--- a/drivers/spi/spi-fsl-dspi.c
+++ b/drivers/spi/spi-fsl-dspi.c
@@ -327,6 +327,7 @@ static int dspi_dma_xfer(struct fsl_dspi *dspi)
 {
        struct fsl_dspi_dma *dma = dspi->dma;
        struct device *dev = &dspi->pdev->dev;
+       struct spi_message *message = dspi->cur_msg;
        int curr_remaining_bytes;
        int bytes_per_buffer;
        int word = 1;
@@ -348,7 +349,10 @@ static int dspi_dma_xfer(struct fsl_dspi *dspi)
                        goto exit;
 
                } else {
-                       curr_remaining_bytes -= dma->curr_xfer_len * word;
+                       const int len = dma->curr_xfer_len * word;
+
+                       curr_remaining_bytes -= len;
+                       message->actual_length += len;
                        if (curr_remaining_bytes < 0)
                                curr_remaining_bytes = 0;
                }
-- 
2.17.1