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spi: omap2-mcspi: Undo broken fix for dma transfer of vmalloced buffer

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This reverts commit 3525e0aac9.

The DMA transfer for RX buffer was not handled correctly in this change.

The actual transfer length for DMA RX can be less than xfer->len in the
specific condition and the last words will be filled after the DMA
completion, but the commit doesn't consider it and the dmaengine is
started with rx_sg mapped by spi core.

The solution for this at least requires more lines than this commit
has inserted.  So revert it for now.

Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
This commit is contained in:
Akinobu Mita 2016-04-09 03:43:15 +09:00 committed by Mark Brown
parent bf16200689
commit 8070954d7c
1 changed files with 45 additions and 17 deletions
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62
drivers/spi/spi-omap2-mcspi.c
View file

@ -423,12 +423,16 @@ static void omap2_mcspi_tx_dma(struct spi_device *spi,
if (mcspi_dma->dma_tx) {
struct dma_async_tx_descriptor *tx;
struct scatterlist sg;
dmaengine_slave_config(mcspi_dma->dma_tx, &cfg);
tx = dmaengine_prep_slave_sg(mcspi_dma->dma_tx, xfer->tx_sg.sgl,
xfer->tx_sg.nents, DMA_MEM_TO_DEV,
DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
sg_init_table(&sg, 1);
sg_dma_address(&sg) = xfer->tx_dma;
sg_dma_len(&sg) = xfer->len;
tx = dmaengine_prep_slave_sg(mcspi_dma->dma_tx, &sg, 1,
DMA_MEM_TO_DEV, DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
if (tx) {
tx->callback = omap2_mcspi_tx_callback;
tx->callback_param = spi;
@ -474,15 +478,20 @@ omap2_mcspi_rx_dma(struct spi_device *spi, struct spi_transfer *xfer,
if (mcspi_dma->dma_rx) {
struct dma_async_tx_descriptor *tx;
struct scatterlist sg;
dmaengine_slave_config(mcspi_dma->dma_rx, &cfg);
if ((l & OMAP2_MCSPI_CHCONF_TURBO) && mcspi->fifo_depth == 0)
dma_count -= es;
tx = dmaengine_prep_slave_sg(mcspi_dma->dma_rx, xfer->rx_sg.sgl,
xfer->rx_sg.nents, DMA_DEV_TO_MEM,
DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
sg_init_table(&sg, 1);
sg_dma_address(&sg) = xfer->rx_dma;
sg_dma_len(&sg) = dma_count;
tx = dmaengine_prep_slave_sg(mcspi_dma->dma_rx, &sg, 1,
DMA_DEV_TO_MEM, DMA_PREP_INTERRUPT |
DMA_CTRL_ACK);
if (tx) {
tx->callback = omap2_mcspi_rx_callback;
tx->callback_param = spi;
@ -496,6 +505,8 @@ omap2_mcspi_rx_dma(struct spi_device *spi, struct spi_transfer *xfer,
omap2_mcspi_set_dma_req(spi, 1, 1);
wait_for_completion(&mcspi_dma->dma_rx_completion);
dma_unmap_single(mcspi->dev, xfer->rx_dma, count,
DMA_FROM_DEVICE);
if (mcspi->fifo_depth > 0)
return count;
@ -608,6 +619,8 @@ omap2_mcspi_txrx_dma(struct spi_device *spi, struct spi_transfer *xfer)
if (tx != NULL) {
wait_for_completion(&mcspi_dma->dma_tx_completion);
dma_unmap_single(mcspi->dev, xfer->tx_dma, xfer->len,
DMA_TO_DEVICE);
if (mcspi->fifo_depth > 0) {
irqstat_reg = mcspi->base + OMAP2_MCSPI_IRQSTATUS;
@ -1074,16 +1087,6 @@ static void omap2_mcspi_cleanup(struct spi_device *spi)
gpio_free(spi->cs_gpio);
}
static bool omap2_mcspi_can_dma(struct spi_master *master,
struct spi_device *spi,
struct spi_transfer *xfer)
{
if (xfer->len < DMA_MIN_BYTES)
return false;
return true;
}
static int omap2_mcspi_work_one(struct omap2_mcspi *mcspi,
struct spi_device *spi, struct spi_transfer *t)
{
@ -1265,6 +1268,32 @@ static int omap2_mcspi_transfer_one(struct spi_master *master,
return -EINVAL;
}
if (len < DMA_MIN_BYTES)
goto skip_dma_map;
if (mcspi_dma->dma_tx && tx_buf != NULL) {
t->tx_dma = dma_map_single(mcspi->dev, (void *) tx_buf,
len, DMA_TO_DEVICE);
if (dma_mapping_error(mcspi->dev, t->tx_dma)) {
dev_dbg(mcspi->dev, "dma %cX %d bytes error\n",
'T', len);
return -EINVAL;
}
}
if (mcspi_dma->dma_rx && rx_buf != NULL) {
t->rx_dma = dma_map_single(mcspi->dev, rx_buf, t->len,
DMA_FROM_DEVICE);
if (dma_mapping_error(mcspi->dev, t->rx_dma)) {
dev_dbg(mcspi->dev, "dma %cX %d bytes error\n",
'R', len);
if (tx_buf != NULL)
dma_unmap_single(mcspi->dev, t->tx_dma,
len, DMA_TO_DEVICE);
return -EINVAL;
}
}
skip_dma_map:
return omap2_mcspi_work_one(mcspi, spi, t);
}
@ -1348,7 +1377,6 @@ static int omap2_mcspi_probe(struct platform_device *pdev)
master->transfer_one = omap2_mcspi_transfer_one;
master->set_cs = omap2_mcspi_set_cs;
master->cleanup = omap2_mcspi_cleanup;
master->can_dma = omap2_mcspi_can_dma;
master->dev.of_node = node;
master->max_speed_hz = OMAP2_MCSPI_MAX_FREQ;
master->min_speed_hz = OMAP2_MCSPI_MAX_FREQ >> 15;