From: Mark Brown broonie@linaro.org
The core implementation of cs_change didn't follow the documentation which says that cs_change in the middle of the transfer means to briefly deassert chip select, instead it followed buggy drivers which change the polarity of chip select. Use a delay of 10us between deassert and reassert simply from pulling numbers out of a hat.
Reported-by: Gerhard Sittig gsi@denx.de Signed-off-by: Mark Brown broonie@linaro.org ---
Compile tested only.
drivers/spi/spi.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c index 121c43b..4eb9bf0 100644 --- a/drivers/spi/spi.c +++ b/drivers/spi/spi.c @@ -754,7 +754,6 @@ static int spi_transfer_one_message(struct spi_master *master, struct spi_message *msg) { struct spi_transfer *xfer; - bool cur_cs = true; bool keep_cs = false; int ret = 0; int ms = 1; @@ -800,8 +799,9 @@ static int spi_transfer_one_message(struct spi_master *master, &msg->transfers)) { keep_cs = true; } else { - cur_cs = !cur_cs; - spi_set_cs(msg->spi, cur_cs); + spi_set_cs(msg->spi, false); + udelay(10); + spi_set_cs(msg->spi, true); } }