* Kalle Valo <kalle.valo@xxxxxxxxx> [080111 09:33]:
> Before transmission of the last word in PIO RX_ONLY mode rx+tx mode
> is enabled:
>
> /* prevent last RX_ONLY read from triggering
> * more word i/o: switch to rx+tx
> */
> if (c == 0 && tx == NULL)
> mcspi_write_cs_reg(spi,
> OMAP2_MCSPI_CHCONF0, l);
>
> But because c is decremented after the test, c will never be zero and
> rx+tx will not be enabled. This breaks RX_ONLY mode PIO transfers.
>
> Fix it by decrementing c already in the beginning of the loop.
>
> Signed-off-by: Kalle Valo <kalle.valo@xxxxxxxxx>
> ---
> drivers/spi/omap2_mcspi.c | 6 +++---
> 1 files changed, 3 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/spi/omap2_mcspi.c b/drivers/spi/omap2_mcspi.c
> index 3cdab13..ea61724 100644
> --- a/drivers/spi/omap2_mcspi.c
> +++ b/drivers/spi/omap2_mcspi.c
> @@ -350,6 +350,7 @@ omap2_mcspi_txrx_pio(struct spi_device *spi, struct spi_transfer *xfer)
> tx = xfer->tx_buf;
>
> do {
> + c -= 1;
> if (tx != NULL) {
> if (mcspi_wait_for_reg_bit(chstat_reg,
> OMAP2_MCSPI_CHSTAT_TXS) < 0) {
> @@ -380,7 +381,6 @@ omap2_mcspi_txrx_pio(struct spi_device *spi, struct spi_transfer *xfer)
> word_len, *(rx - 1));
> #endif
> }
> - c -= 1;
> } while (c);
> } else if (word_len <= 16) {
> u16 *rx;
> @@ -389,6 +389,7 @@ omap2_mcspi_txrx_pio(struct spi_device *spi, struct spi_transfer *xfer)
> rx = xfer->rx_buf;
> tx = xfer->tx_buf;
> do {
> + c -= 2;
> if (tx != NULL) {
> if (mcspi_wait_for_reg_bit(chstat_reg,
> OMAP2_MCSPI_CHSTAT_TXS) < 0) {
> @@ -419,7 +420,6 @@ omap2_mcspi_txrx_pio(struct spi_device *spi, struct spi_transfer *xfer)
> word_len, *(rx - 1));
> #endif
> }
> - c -= 2;
> } while (c);
> } else if (word_len <= 32) {
> u32 *rx;
> @@ -428,6 +428,7 @@ omap2_mcspi_txrx_pio(struct spi_device *spi, struct spi_transfer *xfer)
> rx = xfer->rx_buf;
> tx = xfer->tx_buf;
> do {
> + c -= 4;
> if (tx != NULL) {
> if (mcspi_wait_for_reg_bit(chstat_reg,
> OMAP2_MCSPI_CHSTAT_TXS) < 0) {
> @@ -458,7 +459,6 @@ omap2_mcspi_txrx_pio(struct spi_device *spi, struct spi_transfer *xfer)
> word_len, *(rx - 1));
> #endif
> }
> - c -= 4;
> } while (c);
> }
>
Pushing today.
Tony
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