[PATCH] spi: omap2-mcspi: Remove redundant checks

From: Vignesh Raghavendra
Date: Fri Nov 08 2019 - 23:18:14 EST


Both omap2_mcspi_tx_dma() and omap2_mcspi_rx_dma() are only called from
omap2_mcspi_txrx_dma() and omap2_mcspi_txrx_dma() is always called after
making sure that mcspi_dma->dma_rx and mcspi_dma->dma_tx are not NULL
(see omap2_mcspi_transfer_one()).
Therefore remove redundant NULL checks for omap2_mcspi->dma_tx and
omap2_mcspi->dma_rx pointers in omap2_mcspi_tx_dma() and
omap2_mcspi_rx_dma() respectively.

Signed-off-by: Vignesh Raghavendra <vigneshr@xxxxxx>
---
drivers/spi/spi-omap2-mcspi.c | 105 +++++++++++++++-------------------
1 file changed, 47 insertions(+), 58 deletions(-)

diff --git a/drivers/spi/spi-omap2-mcspi.c b/drivers/spi/spi-omap2-mcspi.c
index 848e03e5f42d..7e2292c11d12 100644
--- a/drivers/spi/spi-omap2-mcspi.c
+++ b/drivers/spi/spi-omap2-mcspi.c
@@ -397,30 +397,26 @@ static void omap2_mcspi_tx_dma(struct spi_device *spi,
{
struct omap2_mcspi *mcspi;
struct omap2_mcspi_dma *mcspi_dma;
+ struct dma_async_tx_descriptor *tx;

mcspi = spi_master_get_devdata(spi->master);
mcspi_dma = &mcspi->dma_channels[spi->chip_select];

- if (mcspi_dma->dma_tx) {
- struct dma_async_tx_descriptor *tx;
+ dmaengine_slave_config(mcspi_dma->dma_tx, &cfg);

- 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);
- if (tx) {
- tx->callback = omap2_mcspi_tx_callback;
- tx->callback_param = spi;
- dmaengine_submit(tx);
- } else {
- /* FIXME: fall back to PIO? */
- }
+ 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);
+ if (tx) {
+ tx->callback = omap2_mcspi_tx_callback;
+ tx->callback_param = spi;
+ dmaengine_submit(tx);
+ } else {
+ /* FIXME: fall back to PIO? */
}
dma_async_issue_pending(mcspi_dma->dma_tx);
omap2_mcspi_set_dma_req(spi, 0, 1);
-
}

static unsigned
@@ -439,6 +435,7 @@ omap2_mcspi_rx_dma(struct spi_device *spi, struct spi_transfer *xfer,
int word_len, element_count;
struct omap2_mcspi_cs *cs = spi->controller_state;
void __iomem *chstat_reg = cs->base + OMAP2_MCSPI_CHSTAT0;
+ struct dma_async_tx_descriptor *tx;

mcspi = spi_master_get_devdata(spi->master);
mcspi_dma = &mcspi->dma_channels[spi->chip_select];
@@ -462,55 +459,47 @@ omap2_mcspi_rx_dma(struct spi_device *spi, struct spi_transfer *xfer,
else /* word_len <= 32 */
element_count = count >> 2;

- if (mcspi_dma->dma_rx) {
- struct dma_async_tx_descriptor *tx;

- dmaengine_slave_config(mcspi_dma->dma_rx, &cfg);
+ dmaengine_slave_config(mcspi_dma->dma_rx, &cfg);

+ /*
+ * Reduce DMA transfer length by one more if McSPI is
+ * configured in turbo mode.
+ */
+ if ((l & OMAP2_MCSPI_CHCONF_TURBO) && mcspi->fifo_depth == 0)
+ transfer_reduction += es;
+
+ if (transfer_reduction) {
+ /* Split sgl into two. The second sgl won't be used. */
+ sizes[0] = count - transfer_reduction;
+ sizes[1] = transfer_reduction;
+ nb_sizes = 2;
+ } else {
/*
- * Reduce DMA transfer length by one more if McSPI is
- * configured in turbo mode.
+ * Don't bother splitting the sgl. This essentially
+ * clones the original sgl.
*/
- if ((l & OMAP2_MCSPI_CHCONF_TURBO) && mcspi->fifo_depth == 0)
- transfer_reduction += es;
-
- if (transfer_reduction) {
- /* Split sgl into two. The second sgl won't be used. */
- sizes[0] = count - transfer_reduction;
- sizes[1] = transfer_reduction;
- nb_sizes = 2;
- } else {
- /*
- * Don't bother splitting the sgl. This essentially
- * clones the original sgl.
- */
- sizes[0] = count;
- nb_sizes = 1;
- }
+ sizes[0] = count;
+ nb_sizes = 1;
+ }

- ret = sg_split(xfer->rx_sg.sgl, xfer->rx_sg.nents,
- 0, nb_sizes,
- sizes,
- sg_out, out_mapped_nents,
- GFP_KERNEL);
+ ret = sg_split(xfer->rx_sg.sgl, xfer->rx_sg.nents, 0, nb_sizes,
+ sizes, sg_out, out_mapped_nents, GFP_KERNEL);

- if (ret < 0) {
- dev_err(&spi->dev, "sg_split failed\n");
- return 0;
- }
+ if (ret < 0) {
+ dev_err(&spi->dev, "sg_split failed\n");
+ return 0;
+ }

- tx = dmaengine_prep_slave_sg(mcspi_dma->dma_rx,
- sg_out[0],
- out_mapped_nents[0],
- DMA_DEV_TO_MEM,
- DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
- if (tx) {
- tx->callback = omap2_mcspi_rx_callback;
- tx->callback_param = spi;
- dmaengine_submit(tx);
- } else {
- /* FIXME: fall back to PIO? */
- }
+ tx = dmaengine_prep_slave_sg(mcspi_dma->dma_rx, sg_out[0],
+ out_mapped_nents[0], DMA_DEV_TO_MEM,
+ DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
+ if (tx) {
+ tx->callback = omap2_mcspi_rx_callback;
+ tx->callback_param = spi;
+ dmaengine_submit(tx);
+ } else {
+ /* FIXME: fall back to PIO? */
}

dma_async_issue_pending(mcspi_dma->dma_rx);
--
2.24.0