diff options
| author | Marek Vasut <marex@denx.de> | 2012-09-04 04:40:17 +0200 |
|---|---|---|
| committer | Mark Brown <broonie@opensource.wolfsonmicro.com> | 2012-09-06 01:42:18 +0200 |
| commit | 727c10e3e54c4404f6842d246b15fe3703d33556 (patch) | |
| tree | f672db2d5614a0c14992b63d6d4c423789e2665a | |
| parent | mxs/spi: Increment the transfer length only if transfer succeeded (diff) | |
| download | linux-727c10e3e54c4404f6842d246b15fe3703d33556.tar.xz linux-727c10e3e54c4404f6842d246b15fe3703d33556.zip | |
mxs/spi: Decrement the DMA/PIO border
This driver checks the length of transfer to be made and based
on this information, either chooses to transfer data via DMA or
PIO. Decrement this border further to gain better performace eg.
during SPI flash writes.
Empiric measurement shows that this gives extra 3kB/s write speed
with a M25P80 flash clocked at 40MHz.
Signed-off-by: Marek Vasut <marex@denx.de>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
| -rw-r--r-- | drivers/spi/spi-mxs.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/spi/spi-mxs.c b/drivers/spi/spi-mxs.c index 138c8523dbba..21e1dcad3914 100644 --- a/drivers/spi/spi-mxs.c +++ b/drivers/spi/spi-mxs.c @@ -445,7 +445,7 @@ static int mxs_spi_transfer_one(struct spi_master *master, * DMA only: 2.164808 seconds, 473.0KB/s * Combined: 1.676276 seconds, 610.9KB/s */ - if (t->len <= 256) { + if (t->len < 32) { writel(BM_SSP_CTRL1_DMA_ENABLE, ssp->base + HW_SSP_CTRL1(ssp) + STMP_OFFSET_REG_CLR); |