[U-Boot] [PATCH] xilinx_spi: 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 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

On 01/22/2014 09:48 AM, Michal Simek 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(-)
Jagan: Can you please add this patch to your custodian tree?
Thanks, Michal

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!
participants (3)
-
Jagan Teki
-
Michal Simek
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Michal Simek