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can: mcp251x: remove custom DMA mapped buffer

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There is no need to duplicate what SPI core already does, i.e. mapping buffers
for DMA capable transfers. This patch removes all related pices of code.

Tested-by: Sean Nyekjaer <sean@geanix.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
This commit is contained in:
Marc Kleine-Budde 2019-08-19 17:08:29 +02:00
parent 6a07c2305a
commit df58525df3
1 changed files with 10 additions and 48 deletions
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58
drivers/net/can/spi/mcp251x.c
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@ -47,7 +47,6 @@
#include <linux/completion.h>
#include <linux/delay.h>
#include <linux/device.h>
#include <linux/dma-mapping.h>
#include <linux/freezer.h>
#include <linux/interrupt.h>
#include <linux/io.h>
@ -202,10 +201,6 @@
#define DEVICE_NAME "mcp251x"
static int mcp251x_enable_dma; /* Enable SPI DMA. Default: 0 (Off) */
module_param(mcp251x_enable_dma, int, 0444);
MODULE_PARM_DESC(mcp251x_enable_dma, "Enable SPI DMA. Default: 0 (Off)");
static const struct can_bittiming_const mcp251x_bittiming_const = {
.name = DEVICE_NAME,
.tseg1_min = 3,
@ -234,8 +229,6 @@ struct mcp251x_priv {
u8 *spi_tx_buf;
u8 *spi_rx_buf;
dma_addr_t spi_tx_dma;
dma_addr_t spi_rx_dma;
struct sk_buff *tx_skb;
int tx_len;
@ -304,13 +297,6 @@ static int mcp251x_spi_trans(struct spi_device *spi, int len)
int ret;
spi_message_init(&m);
if (mcp251x_enable_dma) {
t.tx_dma = priv->spi_tx_dma;
t.rx_dma = priv->spi_rx_dma;
m.is_dma_mapped = 1;
}
spi_message_add_tail(&t, &m);
ret = spi_sync(spi, &m);
@ -1097,42 +1083,18 @@ static int mcp251x_can_probe(struct spi_device *spi)
priv->spi = spi;
mutex_init(&priv->mcp_lock);
/* If requested, allocate DMA buffers */
if (mcp251x_enable_dma) {
spi->dev.coherent_dma_mask = ~0;
/* Minimum coherent DMA allocation is PAGE_SIZE, so allocate
* that much and share it between Tx and Rx DMA buffers.
*/
priv->spi_tx_buf = dmam_alloc_coherent(&spi->dev,
PAGE_SIZE,
&priv->spi_tx_dma,
GFP_DMA);
if (priv->spi_tx_buf) {
priv->spi_rx_buf = (priv->spi_tx_buf + (PAGE_SIZE / 2));
priv->spi_rx_dma = (dma_addr_t)(priv->spi_tx_dma +
(PAGE_SIZE / 2));
} else {
/* Fall back to non-DMA */
mcp251x_enable_dma = 0;
}
priv->spi_tx_buf = devm_kzalloc(&spi->dev, SPI_TRANSFER_BUF_LEN,
GFP_KERNEL);
if (!priv->spi_tx_buf) {
ret = -ENOMEM;
goto error_probe;
}
/* Allocate non-DMA buffers */
if (!mcp251x_enable_dma) {
priv->spi_tx_buf = devm_kzalloc(&spi->dev, SPI_TRANSFER_BUF_LEN,
GFP_KERNEL);
if (!priv->spi_tx_buf) {
ret = -ENOMEM;
goto error_probe;
}
priv->spi_rx_buf = devm_kzalloc(&spi->dev, SPI_TRANSFER_BUF_LEN,
GFP_KERNEL);
if (!priv->spi_rx_buf) {
ret = -ENOMEM;
goto error_probe;
}
priv->spi_rx_buf = devm_kzalloc(&spi->dev, SPI_TRANSFER_BUF_LEN,
GFP_KERNEL);
if (!priv->spi_rx_buf) {
ret = -ENOMEM;
goto error_probe;
}
SET_NETDEV_DEV(net, &spi->dev);