From 99f1cf1c0c2ccdfa251a55cd28e3004963bf6e1a Mon Sep 17 00:00:00 2001 From: Sascha Hauer Date: Tue, 23 Feb 2016 10:23:50 +0100 Subject: spi: imx: drop fallback to PIO 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 Signed-off-by: Mark Brown --- drivers/spi/spi-imx.c | 19 ++++++------------- 1 file changed, 6 insertions(+), 13 deletions(-) (limited to 'drivers/spi') diff --git a/drivers/spi/spi-imx.c b/drivers/spi/spi-imx.c index 6497fc9c2735..a61b1b140523 100644 --- a/drivers/spi/spi-imx.c +++ b/drivers/spi/spi-imx.c @@ -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 tx_nodma; + return -EINVAL; desc_tx->callback = spi_imx_dma_tx_callback; desc_tx->callback_param = (void *)spi_imx; @@ -956,8 +956,10 @@ static int spi_imx_dma_transfer(struct spi_imx_data *spi_imx, desc_rx = dmaengine_prep_slave_sg(master->dma_rx, rx->sgl, rx->nents, DMA_DEV_TO_MEM, DMA_PREP_INTERRUPT | DMA_CTRL_ACK); - if (!desc_rx) - goto rx_nodma; + if (!desc_rx) { + dmaengine_terminate_all(master->dma_tx); + return -EINVAL; + } desc_rx->callback = spi_imx_dma_rx_callback; desc_rx->callback_param = (void *)spi_imx; @@ -1010,12 +1012,6 @@ static int spi_imx_dma_transfer(struct spi_imx_data *spi_imx, ret = transfer->len; return ret; - -rx_nodma: - dmaengine_terminate_all(master->dma_tx); -tx_nodma: - 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, @@ -1042,15 +1038,12 @@ 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; -- cgit v1.2.3-70-g09d2