From 999c39a45f115a17f6b894e3a9cd894c598fb2e0 Mon Sep 17 00:00:00 2001 From: Michal Simek Date: Wed, 22 Jan 2014 09:48:55 +0100 Subject: spi: xilinx: Move timeout calculation out of the loop Timeout calculation should be out of the data loop. This patch increase spi bandwidth for 30%. Signed-off-by: Michal Simek Reviewed-by: Jagannadha Sutradharudu Teki --- drivers/spi/xilinx_spi.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) (limited to 'drivers/spi') 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); -- cgit v1.1