[linux-yocto] [PATCH 4/4] Revert "spi/pxa2xx: auto switch between PIO and DMA with configurable threshold size"

[chong.yi.chai at intel.com]

From: "Chai, Chong Yi" <chong.yi.chai at intel.com>

This reverts commit afe9c4b82e119cd9e8e69ef2dbae1191375bfb51.

Signed-off-by: Chai, Chong Yi <chong.yi.chai at intel.com>
---
 drivers/spi/spi-pxa2xx.c        | 17 ++---------------
 drivers/spi/spidev.c            |  2 --
 include/linux/spi/spi.h         |  2 --
 include/uapi/linux/spi/spidev.h |  2 --
 4 files changed, 2 insertions(+), 21 deletions(-)

diff --git a/drivers/spi/spi-pxa2xx.c b/drivers/spi/spi-pxa2xx.c
index 69883b8..5d71e61 100644
--- a/drivers/spi/spi-pxa2xx.c
+++ b/drivers/spi/spi-pxa2xx.c
@@ -619,7 +619,6 @@ static void pump_transfers(unsigned long data)
 	u32 cr1;
 	u32 dma_thresh = drv_data->cur_chip->dma_threshold;
 	u32 dma_burst = drv_data->cur_chip->dma_burst_size;
-	u8 auto_pio_dma_use_pio;
 
 	/* Get current state information */
 	message = drv_data->cur_msg;
@@ -653,20 +652,8 @@ static void pump_transfers(unsigned long data)
 			cs_deassert(drv_data);
 	}
 
-	/*
-	 * Check if in auto switch PIO/DMA mode.
-	 * If true, use PIO if the length is less than threshold value.
-	 */
-	auto_pio_dma_use_pio = chip->enable_dma ? 0 : 1;
-	if (transfer->auto_pio_dma_mode) {
-		if (transfer->len <= transfer->auto_pio_dma_threshold) {
-			auto_pio_dma_use_pio = 1;
-		}
-	}
-
 	/* Check if we can DMA this transfer */
-	if ((!pxa2xx_spi_dma_is_possible(transfer->len) && chip->enable_dma)
-		|| auto_pio_dma_use_pio) {
+	if (!pxa2xx_spi_dma_is_possible(transfer->len) && chip->enable_dma) {
 
 		/* reject already-mapped transfers; PIO won't always work */
 		if (message->is_dma_mapped
@@ -760,7 +747,7 @@ static void pump_transfers(unsigned long data)
 	message->state = RUNNING_STATE;
 
 	drv_data->dma_mapped = 0;
-	if (pxa2xx_spi_dma_is_possible(drv_data->len) && !auto_pio_dma_use_pio)
+	if (pxa2xx_spi_dma_is_possible(drv_data->len))
 		drv_data->dma_mapped = pxa2xx_spi_map_dma_buffers(drv_data);
 	if (drv_data->dma_mapped) {
 
diff --git a/drivers/spi/spidev.c b/drivers/spi/spidev.c
index e14c7c0..2fe5b61 100644
--- a/drivers/spi/spidev.c
+++ b/drivers/spi/spidev.c
@@ -271,8 +271,6 @@ static int spidev_message(struct spidev_data *spidev,
 		k_tmp->bits_per_word = u_tmp->bits_per_word;
 		k_tmp->delay_usecs = u_tmp->delay_usecs;
 		k_tmp->speed_hz = u_tmp->speed_hz;
-		k_tmp->auto_pio_dma_mode = u_tmp->auto_pio_dma_mode;
-		k_tmp->auto_pio_dma_threshold = u_tmp->auto_pio_dma_threshold;
 #ifdef VERBOSE
 		dev_dbg(&spidev->spi->dev,
 			"  xfer len %zd %s%s%s%dbits %u usec %uHz\n",
diff --git a/include/linux/spi/spi.h b/include/linux/spi/spi.h
index d1af9a1..36c86ef 100644
--- a/include/linux/spi/spi.h
+++ b/include/linux/spi/spi.h
@@ -620,8 +620,6 @@ struct spi_transfer {
 	u8		bits_per_word;
 	u16		delay_usecs;
 	u32		speed_hz;
-	u8		auto_pio_dma_mode;
-	u32		auto_pio_dma_threshold;
 
 	struct list_head transfer_list;
 };
diff --git a/include/uapi/linux/spi/spidev.h b/include/uapi/linux/spi/spidev.h
index c5ed56d..52d9ed0 100644
--- a/include/uapi/linux/spi/spidev.h
+++ b/include/uapi/linux/spi/spidev.h
@@ -92,8 +92,6 @@ struct spi_ioc_transfer {
 	__u16		delay_usecs;
 	__u8		bits_per_word;
 	__u8		cs_change;
-	__u8		auto_pio_dma_mode;
-	__u32		auto_pio_dma_threshold;
 	__u32		pad;
 
 	/* If the contents of 'struct spi_ioc_transfer' ever change
-- 
1.9.1