[U-Boot] [PATCH] xilinx_spi: Move timeout calculation out of the loop
Jagan Teki
jagannadh.teki at gmail.com
Tue Feb 4 18:16:53 CET 2014
On Wed, Jan 22, 2014 at 2:18 PM, Michal Simek <michal.simek at xilinx.com> wrote:
> Timeout calculation should be out of the data loop.
> This patch increase spi bandwidth for 30%.
>
> Signed-off-by: Michal Simek <michal.simek at xilinx.com>
> ---
>
> drivers/spi/xilinx_spi.c | 8 +++++---
> 1 file changed, 5 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/spi/xilinx_spi.c b/drivers/spi/xilinx_spi.c
> index 5ac0184..56d99d1 100644
> --- a/drivers/spi/xilinx_spi.c
> +++ b/drivers/spi/xilinx_spi.c
> @@ -149,6 +149,7 @@ int spi_xfer(struct spi_slave *slave, unsigned int bitlen, const void *dout,
> const unsigned char *txp = dout;
> unsigned char *rxp = din;
> unsigned rxecount = 17; /* max. 16 elements in FIFO, leftover 1 */
> + unsigned global_timeout;
>
> debug("%s: bus:%i cs:%i bitlen:%i bytes:%i flags:%lx\n", __func__,
> slave->bus, slave->cs, bitlen, bytes, flags);
> @@ -176,11 +177,12 @@ int spi_xfer(struct spi_slave *slave, unsigned int bitlen, const void *dout,
> if (flags & SPI_XFER_BEGIN)
> spi_cs_activate(slave);
>
> - while (bytes--) {
> - unsigned timeout = /* at least 1usec or greater, leftover 1 */
> - xilspi->freq > XILSPI_MAX_XFER_BITS * 1000000 ? 2 :
> + /* at least 1usec or greater, leftover 1 */
> + global_timeout = xilspi->freq > XILSPI_MAX_XFER_BITS * 1000000 ? 2 :
> (XILSPI_MAX_XFER_BITS * 1000000 / xilspi->freq) + 1;
>
> + while (bytes--) {
> + unsigned timeout = global_timeout;
> /* get Tx element from data out buffer and count up */
> unsigned char d = txp ? *txp++ : CONFIG_XILINX_SPI_IDLE_VAL;
> debug("%s: tx:%x ", __func__, d);
> --
> 1.8.2.3
>
Applied to u-boot-spi/master
thanks!
--
Jagan.
More information about the U-Boot
mailing list