[PATCH] spi: omap2-mcspi: Reorder the wait_for_completion for tx

From: Shubhrajyoti D
Date: Tue Nov 06 2012 - 04:17:42 EST


The commit d7b4394e[Cleanup the omap2_mcspi_txrx_dma function]
changed the wait_for_completion order. Move the wait so that the
rx doesnot wait for the tx to complete.

Reported-and-tested-by: SÃrensen, Stefan <Sorensen@xxxxxxxxxxx>
Signed-off-by: Shubhrajyoti D <shubhrajyoti@xxxxxx>
---
drivers/spi/spi-omap2-mcspi.c | 39 +++++++++++++++++++--------------------
1 files changed, 19 insertions(+), 20 deletions(-)

diff --git a/drivers/spi/spi-omap2-mcspi.c b/drivers/spi/spi-omap2-mcspi.c
index bcfd062..251f6d0 100644
--- a/drivers/spi/spi-omap2-mcspi.c
+++ b/drivers/spi/spi-omap2-mcspi.c
@@ -323,18 +323,13 @@ static void omap2_mcspi_tx_dma(struct spi_device *spi,
struct omap2_mcspi *mcspi;
struct omap2_mcspi_dma *mcspi_dma;
unsigned int count;
- u8 * rx;
const u8 * tx;
- void __iomem *chstat_reg;
- struct omap2_mcspi_cs *cs = spi->controller_state;

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

- rx = xfer->rx_buf;
tx = xfer->tx_buf;
- chstat_reg = cs->base + OMAP2_MCSPI_CHSTAT0;

if (mcspi_dma->dma_tx) {
struct dma_async_tx_descriptor *tx;
@@ -359,19 +354,6 @@ static void omap2_mcspi_tx_dma(struct spi_device *spi,
dma_async_issue_pending(mcspi_dma->dma_tx);
omap2_mcspi_set_dma_req(spi, 0, 1);

- wait_for_completion(&mcspi_dma->dma_tx_completion);
- dma_unmap_single(mcspi->dev, xfer->tx_dma, count,
- DMA_TO_DEVICE);
-
- /* for TX_ONLY mode, be sure all words have shifted out */
- if (rx == NULL) {
- if (mcspi_wait_for_reg_bit(chstat_reg,
- OMAP2_MCSPI_CHSTAT_TXS) < 0)
- dev_err(&spi->dev, "TXS timed out\n");
- else if (mcspi_wait_for_reg_bit(chstat_reg,
- OMAP2_MCSPI_CHSTAT_EOT) < 0)
- dev_err(&spi->dev, "EOT timed out\n");
- }
}

static unsigned
@@ -492,6 +474,7 @@ omap2_mcspi_txrx_dma(struct spi_device *spi, struct spi_transfer *xfer)
struct dma_slave_config cfg;
enum dma_slave_buswidth width;
unsigned es;
+ void __iomem *chstat_reg;

mcspi = spi_master_get_devdata(spi->master);
mcspi_dma = &mcspi->dma_channels[spi->chip_select];
@@ -526,8 +509,24 @@ omap2_mcspi_txrx_dma(struct spi_device *spi, struct spi_transfer *xfer)
omap2_mcspi_tx_dma(spi, xfer, cfg);

if (rx != NULL)
- return omap2_mcspi_rx_dma(spi, xfer, cfg, es);
-
+ count = omap2_mcspi_rx_dma(spi, xfer, cfg, es);
+
+ if (tx != NULL) {
+ chstat_reg = cs->base + OMAP2_MCSPI_CHSTAT0;
+ wait_for_completion(&mcspi_dma->dma_tx_completion);
+ dma_unmap_single(mcspi->dev, xfer->tx_dma, xfer->len,
+ DMA_TO_DEVICE);
+
+ /* for TX_ONLY mode, be sure all words have shifted out */
+ if (rx == NULL) {
+ if (mcspi_wait_for_reg_bit(chstat_reg,
+ OMAP2_MCSPI_CHSTAT_TXS) < 0)
+ dev_err(&spi->dev, "TXS timed out\n");
+ else if (mcspi_wait_for_reg_bit(chstat_reg,
+ OMAP2_MCSPI_CHSTAT_EOT) < 0)
+ dev_err(&spi->dev, "EOT timed out\n");
+ }
+ }
return count;
}

--
1.7.5.4

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/