@@ -945,7 +945,7 @@ static int spi_imx_dma_transfer(struct spi_imx_data *spi_imx,
tx->sgl, tx->nents, DMA_MEM_TO_DEV,
DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
if (!desc_tx)
- goto no_dma;
+ return -EINVAL;
desc_tx->callback = spi_imx_dma_tx_callback;
desc_tx->callback_param = (void *)spi_imx;
@@ -957,7 +957,7 @@ static int spi_imx_dma_transfer(struct spi_imx_data *spi_imx,
rx->sgl, rx->nents, DMA_DEV_TO_MEM,
DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
if (!desc_rx)
- goto no_dma;
+ return -EINVAL;
desc_rx->callback = spi_imx_dma_rx_callback;
desc_rx->callback_param = (void *)spi_imx;
@@ -1010,10 +1010,6 @@ static int spi_imx_dma_transfer(struct spi_imx_data *spi_imx,
ret = transfer->len;
return ret;
-
-no_dma:
- dev_warn_once(spi_imx->dev, "DMA not available, falling back to PIO\n");
- return -EAGAIN;
}
static int spi_imx_pio_transfer(struct spi_device *spi,
@@ -1040,15 +1036,12 @@ static int spi_imx_pio_transfer(struct spi_device *spi,
static int spi_imx_transfer(struct spi_device *spi,
struct spi_transfer *transfer)
{
- int ret;
struct spi_imx_data *spi_imx = spi_master_get_devdata(spi->master);
if (spi_imx->bitbang.master->can_dma &&
spi_imx_can_dma(spi_imx->bitbang.master, spi, transfer)) {
spi_imx->usedma = true;
- ret = spi_imx_dma_transfer(spi_imx, transfer);
- if (ret != -EAGAIN)
- return ret;
+ return spi_imx_dma_transfer(spi_imx, transfer);
}
spi_imx->usedma = false;
At the moment the driver decides to fallback to PIO mode the buffers are already mapped for DMA. It's a bug to access them with the CPU afterwards, so we cannot just fallback to PIO mode. It should not be necessary anyway, since we only use DMA when we verified that it's possible in the fist place, so when prep_slave_sg fails it's a bug, either in the SDMA driver or in the can_dma implementation. Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de> --- drivers/spi/spi-imx.c | 13 +++---------- 1 file changed, 3 insertions(+), 10 deletions(-)