[patch 2.6.24 4/6] spi_bfin: wait for tx to complete on full duplex paths

[patch 2.6.24 4/6] spi_bfin: wait for tx to complete on full duplex paths

[David Brownell]

From: Bryan Wu <bryan.wu-OyLXuOCK7orQT0dZR+AlfA@public.gmane.org>

Full duplex SPI operation should not read a dummy byte at the first
transfer.  Bug and fix by Jean-Christian de Rivaz <jc-WsDXB8FQtm4@public.gmane.org>:

http://blackfin.uclinux.org/gf/project/uclinux-dist/tracker/?action=TrackerItemEdit&tracker_item_id=3678

Signed-off-by: Jean-Christian de Rivaz <jc-WsDXB8FQtm4@public.gmane.org>
Signed-off-by: Bryan Wu <bryan.wu-OyLXuOCK7orQT0dZR+AlfA@public.gmane.org>
Signed-off-by: David Brownell <dbrownell-Rn4VEauK+AKRv+LV9MX5uipxlwaOVQ5f@public.gmane.org>
---
 drivers/spi/spi_bfin5xx.c |   18 +++---------------
 1 file changed, 3 insertions(+), 15 deletions(-)

--- g26.orig/drivers/spi/spi_bfin5xx.c	2008-01-31 11:52:00.000000000 -0800
+++ g26/drivers/spi/spi_bfin5xx.c	2008-01-31 11:52:01.000000000 -0800
@@ -358,14 +358,10 @@ static void u8_cs_chg_reader(struct driv
 
 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 dri
 
 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 dri
 {
 	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();

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