Re: [U-Boot] [PATCH] xilinx_spi: Move timeout calculation out of the loop

On Wed, Jan 22, 2014 at 2:18 PM, Michal Simek michal.simek@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@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!