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| author | Bryan Wu <bryan.wu@analog.com> | 2008-02-06 01:38:19 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@woody.linux-foundation.org> | 2008-02-06 10:41:11 -0800 |
| commit | 4fd432d9c7ac9a14e750d2ab0c91bc151e9af32e (patch) | |
| tree | 29880eba49d051bb6663e5c2c583ff1fe5067bc3 /drivers/spi | |
| parent | e26aa015dd34d5768b80815836ad60e8495e9553 (diff) | |
| download | linux-4fd432d9c7ac9a14e750d2ab0c91bc151e9af32e.tar.gz linux-4fd432d9c7ac9a14e750d2ab0c91bc151e9af32e.tar.bz2 linux-4fd432d9c7ac9a14e750d2ab0c91bc151e9af32e.zip | |
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 <jc@eclis.ch>:
http://blackfin.uclinux.org/gf/project/uclinux-dist/tracker/?action=TrackerItemEdit&tracker_item_id=3678
Signed-off-by: Jean-Christian de Rivaz <jc@eclis.ch>
Signed-off-by: Bryan Wu <bryan.wu@analog.com>
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'drivers/spi')
| -rw-r--r-- | drivers/spi/spi_bfin5xx.c | 18 |
1 files 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(); |