* [patch 2.6.25] spi_bfin5xx use PIO for full duplex, not DMA
@ 2008-04-30 22:47 David Brownell
[not found] ` <200804301547.46579.david-b-yBeKhBN/0LDR7s880joybQ@public.gmane.org>
0 siblings, 1 reply; 2+ messages in thread
From: David Brownell @ 2008-04-30 22:47 UTC (permalink / raw)
To: Andrew Morton
Cc: spi-devel-general-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f, Vitja Makarov
From: Vitja Makarov <vitja.makarov-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
Use PIO for full-duplex transfers, instead of DMA.
Signed-off-by: Vitja Makarov <vitja.makarov-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
Signed-off-by: Bryan Wu <cooloney-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>
Signed-off-by: David Brownell <dbrownell-Rn4VEauK+AKRv+LV9MX5uipxlwaOVQ5f@public.gmane.org>
---
drivers/spi/spi_bfin5xx.c | 7 +++++--
1 file changed, 5 insertions(+), 2 deletions(-)
--- at91.orig/drivers/spi/spi_bfin5xx.c 2008-04-15 10:29:21.000000000 -0700
+++ at91/drivers/spi/spi_bfin5xx.c 2008-04-30 15:44:26.000000000 -0700
@@ -608,6 +608,7 @@ static void pump_transfers(unsigned long
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
}
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
* 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
/* 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));
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^ permalink raw reply [flat|nested] 2+ messages in thread
* Re: [patch 2.6.25] spi_bfin5xx use PIO for full duplex, not DMA
[not found] ` <200804301547.46579.david-b-yBeKhBN/0LDR7s880joybQ@public.gmane.org>
@ 2008-04-30 22:53 ` Andrew Morton
0 siblings, 0 replies; 2+ messages in thread
From: Andrew Morton @ 2008-04-30 22:53 UTC (permalink / raw)
To: David Brownell
Cc: spi-devel-general-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f,
vitja.makarov-Re5JQEeQqe8AvxtiuMwx3w
On Wed, 30 Apr 2008 15:47:46 -0700
David Brownell <david-b-yBeKhBN/0LDR7s880joybQ@public.gmane.org> wrote:
> + u8 full_duplex = 0;
that's a bool ;)
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2008-04-30 22:47 [patch 2.6.25] spi_bfin5xx use PIO for full duplex, not DMA David Brownell
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2008-04-30 22:53 ` Andrew Morton
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