From 4fd432d9c7ac9a14e750d2ab0c91bc151e9af32e Mon Sep 17 00:00:00 2001 From: Bryan Wu Date: Wed, 6 Feb 2008 01:38:19 -0800 Subject: [PATCH] spi_bfin: wait for tx to complete on full duplex paths Full duplex SPI operation should not read a dummy byte at the first transfer. Bug and fix by Jean-Christian de Rivaz : http://blackfin.uclinux.org/gf/project/uclinux-dist/tracker/?action=TrackerItemEdit&tracker_item_id=3678 Signed-off-by: Jean-Christian de Rivaz Signed-off-by: Bryan Wu Signed-off-by: David Brownell Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- drivers/spi/spi_bfin5xx.c | 18 +++--------------- 1 file changed, 3 insertions(+), 15 deletions(-) diff --git a/drivers/spi/spi_bfin5xx.c b/drivers/spi/spi_bfin5xx.c index ce4692cdb3b2..f61b5eeb0427 100644 --- a/drivers/spi/spi_bfin5xx.c +++ b/drivers/spi/spi_bfin5xx.c @@ -358,14 +358,10 @@ static void u8_cs_chg_reader(struct driver_data *drv_data) static void u8_duplex(struct driver_data *drv_data) { - /* poll for SPI completion before start */ - while (!(read_STAT(drv_data) & BIT_STAT_SPIF)) - cpu_relax(); - /* in duplex mode, clk is triggered by writing of TDBR */ while (drv_data->rx < drv_data->rx_end) { write_TDBR(drv_data, (*(u8 *) (drv_data->tx))); - while (read_STAT(drv_data) & BIT_STAT_TXS) + while (!(read_STAT(drv_data) & BIT_STAT_SPIF)) cpu_relax(); while (!(read_STAT(drv_data) & BIT_STAT_RXS)) cpu_relax(); @@ -495,14 +491,10 @@ static void u16_cs_chg_reader(struct driver_data *drv_data) static void u16_duplex(struct driver_data *drv_data) { - /* poll for SPI completion before start */ - while (!(read_STAT(drv_data) & BIT_STAT_SPIF)) - cpu_relax(); - /* in duplex mode, clk is triggered by writing of TDBR */ while (drv_data->tx < drv_data->tx_end) { write_TDBR(drv_data, (*(u16 *) (drv_data->tx))); - while (read_STAT(drv_data) & BIT_STAT_TXS) + while (!(read_STAT(drv_data) & BIT_STAT_SPIF)) cpu_relax(); while (!(read_STAT(drv_data) & BIT_STAT_RXS)) cpu_relax(); @@ -516,15 +508,11 @@ static void u16_cs_chg_duplex(struct driver_data *drv_data) { struct chip_data *chip = drv_data->cur_chip; - /* poll for SPI completion before start */ - while (!(read_STAT(drv_data) & BIT_STAT_SPIF)) - cpu_relax(); - while (drv_data->tx < drv_data->tx_end) { cs_active(drv_data, chip); write_TDBR(drv_data, (*(u16 *) (drv_data->tx))); - while (read_STAT(drv_data) & BIT_STAT_TXS) + while (!(read_STAT(drv_data) & BIT_STAT_SPIF)) cpu_relax(); while (!(read_STAT(drv_data) & BIT_STAT_RXS)) cpu_relax(); -- 2.20.1