[PATCH 2/5] Blackfin SPI Driver: add comment about full duplex dma according to David Brownell

Bryan Wu
2009-02-05T10:06:36Z

From: Mike Frysinger <vapier.adi@gmail.com>

Signed-off-by: Mike Frysinger <vapier.adi@gmail.com>
Signed-off-by: Bryan Wu <cooloney@kernel.org>
---
drivers/spi/spi_bfin5xx.c | 7 ++++---
1 files changed, 4 insertions(+), 3 deletions(-)

diff --git a/drivers/spi/spi_bfin5xx.c b/drivers/spi/spi_bfin5xx.c
index 74c5bb9..ce24d5e 100644
--- a/drivers/spi/spi_bfin5xx.c
+++ b/drivers/spi/spi_bfin5xx.c
@@ -766,9 +766,10 @@ static void bfin_spi_pump_transfers(unsigned long data)
width, transfer->len);

/*
- * Try to map dma buffer and do a dma transfer if
- * successful use different way to r/w according to
- * drv_data->cur_chip->enable_dma
+ * Try to map dma buffer and do a dma transfer. If successful use,
+ * different way to r/w according to the enable_dma settings and if
+ * we are not doing a full duplex transfer (since the hardware does
+ * not support full duplex DMA transfers).
*/
if (!full_duplex && drv_data->cur_chip->enable_dma
&& drv_data->len > 6) {
--
1.5.6.3