From 8eeb12e5a2486ab958fa27ec97e71dabf234b73b Mon Sep 17 00:00:00 2001 From: Vitja Makarov Date: Thu, 1 May 2008 04:35:03 -0700 Subject: [PATCH] spi_bfin5xx: use PIO for full duplex, not DMA Use PIO for full-duplex transfers, instead of DMA. Signed-off-by: Vitja Makarov 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 | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) diff --git a/drivers/spi/spi_bfin5xx.c b/drivers/spi/spi_bfin5xx.c index a9ac1fdb30..7fea3cf458 100644 --- a/drivers/spi/spi_bfin5xx.c +++ b/drivers/spi/spi_bfin5xx.c @@ -608,6 +608,7 @@ static void pump_transfers(unsigned long data) u8 width; u16 cr, dma_width, dma_config; u32 tranf_success = 1; + u8 full_duplex = 0; /* Get current state information */ message = drv_data->cur_msg; @@ -658,6 +659,7 @@ static void pump_transfers(unsigned long data) } if (transfer->rx_buf != NULL) { + full_duplex = transfer->tx_buf != NULL; drv_data->rx = transfer->rx_buf; drv_data->rx_end = drv_data->rx + transfer->len; dev_dbg(&drv_data->pdev->dev, "rx_buf is %p, rx_end is %p\n", @@ -740,7 +742,8 @@ static void pump_transfers(unsigned long data) * successful use different way to r/w according to * drv_data->cur_chip->enable_dma */ - if (drv_data->cur_chip->enable_dma && drv_data->len > 6) { + if (!full_duplex && drv_data->cur_chip->enable_dma + && drv_data->len > 6) { disable_dma(drv_data->dma_channel); clear_dma_irqstat(drv_data->dma_channel); @@ -828,7 +831,7 @@ static void pump_transfers(unsigned long data) /* IO mode write then read */ dev_dbg(&drv_data->pdev->dev, "doing IO transfer\n"); - if (drv_data->tx != NULL && drv_data->rx != NULL) { + if (full_duplex) { /* full duplex mode */ BUG_ON((drv_data->tx_end - drv_data->tx) != (drv_data->rx_end - drv_data->rx)); -- 2.39.5