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authorBrian Niebuhr <bniebuhr@efjohnson.com>2010-10-05 11:38:41 +0530
committerSekhar Nori <nsekhar@ti.com>2010-11-18 18:38:35 +0530
commit9b189fd7584a1d8c68334dd1bc47b363877b314e (patch)
treeb501c938d169bbd948ef434c50aaf74ed2036bb1 /drivers/spi/davinci_spi.c
parent523c37e7006522e778a1fd0aea2746ceb788572f (diff)
spi: davinci: handle DMA completion errors correctly
Do not simply clean the DMA channel on a DMA completion error. Instead, use wcount and rcount members of davinci_spi to detecion non-completion of DMA and signal EIO to the application. Signed-off-by: Brian Niebuhr <bniebuhr@efjohnson.com> Tested-By: Michael Williamson <michael.williamson@criticallink.com> Signed-off-by: Sekhar Nori <nsekhar@ti.com>
Diffstat (limited to 'drivers/spi/davinci_spi.c')
-rw-r--r--drivers/spi/davinci_spi.c63
1 files changed, 36 insertions, 27 deletions
diff --git a/drivers/spi/davinci_spi.c b/drivers/spi/davinci_spi.c
index 975c2a228d0..a47947da17a 100644
--- a/drivers/spi/davinci_spi.c
+++ b/drivers/spi/davinci_spi.c
@@ -388,24 +388,26 @@ static int davinci_spi_setup_transfer(struct spi_device *spi,
static void davinci_spi_dma_rx_callback(unsigned lch, u16 ch_status, void *data)
{
- struct davinci_spi_dma *davinci_spi_dma = data;
+ struct davinci_spi *davinci_spi = data;
+ struct davinci_spi_dma *davinci_spi_dma = &davinci_spi->dma_channels;
+
+ edma_stop(davinci_spi_dma->dma_rx_channel);
if (ch_status == DMA_COMPLETE)
- edma_stop(davinci_spi_dma->dma_rx_channel);
- else
- edma_clean_channel(davinci_spi_dma->dma_rx_channel);
+ davinci_spi->rcount = 0;
complete(&davinci_spi_dma->dma_rx_completion);
}
static void davinci_spi_dma_tx_callback(unsigned lch, u16 ch_status, void *data)
{
- struct davinci_spi_dma *davinci_spi_dma = data;
+ struct davinci_spi *davinci_spi = data;
+ struct davinci_spi_dma *davinci_spi_dma = &davinci_spi->dma_channels;
+
+ edma_stop(davinci_spi_dma->dma_tx_channel);
if (ch_status == DMA_COMPLETE)
- edma_stop(davinci_spi_dma->dma_tx_channel);
- else
- edma_clean_channel(davinci_spi_dma->dma_tx_channel);
+ davinci_spi->wcount = 0;
complete(&davinci_spi_dma->dma_tx_completion);
}
@@ -632,7 +634,6 @@ static int davinci_spi_bufs_dma(struct spi_device *spi, struct spi_transfer *t)
{
struct davinci_spi *davinci_spi;
int int_status = 0;
- int count;
unsigned rx_buf_count;
struct davinci_spi_dma *davinci_spi_dma;
int data_type, ret;
@@ -648,20 +649,20 @@ static int davinci_spi_bufs_dma(struct spi_device *spi, struct spi_transfer *t)
davinci_spi_dma = &davinci_spi->dma_channels;
+ /* convert len to words based on bits_per_word */
+ data_type = davinci_spi->bytes_per_word[spi->chip_select];
+
tx_reg = (unsigned long)davinci_spi->pbase + SPIDAT1;
rx_reg = (unsigned long)davinci_spi->pbase + SPIBUF;
davinci_spi->tx = t->tx_buf;
davinci_spi->rx = t->rx_buf;
-
- /* convert len to words based on bits_per_word */
- data_type = davinci_spi->bytes_per_word[spi->chip_select];
+ davinci_spi->wcount = t->len / data_type;
+ davinci_spi->rcount = davinci_spi->wcount;
init_completion(&davinci_spi_dma->dma_rx_completion);
init_completion(&davinci_spi_dma->dma_tx_completion);
- count = t->len / data_type; /* the number of elements */
-
/* disable all interrupts for dma transfers */
clear_io_bits(davinci_spi->base + SPIINT, SPIINT_MASKALL);
/* Enable SPI */
@@ -680,18 +681,18 @@ static int davinci_spi_bufs_dma(struct spi_device *spi, struct spi_transfer *t)
*/
if (t->tx_buf) {
- t->tx_dma = dma_map_single(&spi->dev, (void *)t->tx_buf, count,
- DMA_TO_DEVICE);
+ t->tx_dma = dma_map_single(&spi->dev, (void *)t->tx_buf,
+ davinci_spi->wcount, DMA_TO_DEVICE);
if (dma_mapping_error(&spi->dev, t->tx_dma)) {
- dev_dbg(sdev, "Unable to DMA map a %d bytes"
- " TX buffer\n", count);
+ dev_dbg(sdev, "Unable to DMA map %d bytes TX buffer\n",
+ davinci_spi->wcount);
return -ENOMEM;
}
}
param.opt = TCINTEN | EDMA_TCC(davinci_spi_dma->dma_tx_channel);
param.src = t->tx_buf ? t->tx_dma : tx_reg;
- param.a_b_cnt = count << 16 | data_type;
+ param.a_b_cnt = davinci_spi->wcount << 16 | data_type;
param.dst = tx_reg;
param.src_dst_bidx = t->tx_buf ? data_type : 0;
param.link_bcntrld = 0xffff;
@@ -715,7 +716,7 @@ static int davinci_spi_bufs_dma(struct spi_device *spi, struct spi_transfer *t)
if (t->rx_buf) {
rx_buf = t->rx_buf;
- rx_buf_count = count;
+ rx_buf_count = davinci_spi->rcount;
} else {
rx_buf = davinci_spi->rx_tmp_buf;
rx_buf_count = sizeof(davinci_spi->rx_tmp_buf);
@@ -727,13 +728,14 @@ static int davinci_spi_bufs_dma(struct spi_device *spi, struct spi_transfer *t)
dev_dbg(sdev, "Couldn't DMA map a %d bytes RX buffer\n",
rx_buf_count);
if (t->tx_buf)
- dma_unmap_single(NULL, t->tx_dma, count, DMA_TO_DEVICE);
+ dma_unmap_single(NULL, t->tx_dma, davinci_spi->wcount,
+ DMA_TO_DEVICE);
return -ENOMEM;
}
param.opt = TCINTEN | EDMA_TCC(davinci_spi_dma->dma_rx_channel);
param.src = rx_reg;
- param.a_b_cnt = count << 16 | data_type;
+ param.a_b_cnt = davinci_spi->rcount << 16 | data_type;
param.dst = t->rx_dma;
param.src_dst_bidx = (t->rx_buf ? data_type : 0) << 16;
param.link_bcntrld = 0xffff;
@@ -754,7 +756,8 @@ static int davinci_spi_bufs_dma(struct spi_device *spi, struct spi_transfer *t)
wait_for_completion_interruptible(&davinci_spi_dma->dma_rx_completion);
if (t->tx_buf)
- dma_unmap_single(NULL, t->tx_dma, count, DMA_TO_DEVICE);
+ dma_unmap_single(NULL, t->tx_dma, davinci_spi->wcount,
+ DMA_TO_DEVICE);
dma_unmap_single(NULL, t->rx_dma, rx_buf_count, DMA_FROM_DEVICE);
@@ -770,15 +773,21 @@ static int davinci_spi_bufs_dma(struct spi_device *spi, struct spi_transfer *t)
if (ret != 0)
return ret;
+ if (davinci_spi->rcount != 0 || davinci_spi->wcount != 0) {
+ dev_err(sdev, "SPI data transfer error\n");
+ return -EIO;
+ }
+
return t->len;
}
-static int davinci_spi_request_dma(struct davinci_spi_dma *davinci_spi_dma)
+static int davinci_spi_request_dma(struct davinci_spi *davinci_spi)
{
int r;
+ struct davinci_spi_dma *davinci_spi_dma = &davinci_spi->dma_channels;
r = edma_alloc_channel(davinci_spi_dma->dma_rx_channel,
- davinci_spi_dma_rx_callback, davinci_spi_dma,
+ davinci_spi_dma_rx_callback, davinci_spi,
davinci_spi_dma->eventq);
if (r < 0) {
pr_err("Unable to request DMA channel for SPI RX\n");
@@ -787,7 +796,7 @@ static int davinci_spi_request_dma(struct davinci_spi_dma *davinci_spi_dma)
}
r = edma_alloc_channel(davinci_spi_dma->dma_tx_channel,
- davinci_spi_dma_tx_callback, davinci_spi_dma,
+ davinci_spi_dma_tx_callback, davinci_spi,
davinci_spi_dma->eventq);
if (r < 0) {
pr_err("Unable to request DMA channel for SPI TX\n");
@@ -929,7 +938,7 @@ static int davinci_spi_probe(struct platform_device *pdev)
davinci_spi->dma_channels.dma_tx_channel = dma_tx_chan;
davinci_spi->dma_channels.eventq = dma_eventq;
- ret = davinci_spi_request_dma(&davinci_spi->dma_channels);
+ ret = davinci_spi_request_dma(davinci_spi);
if (ret)
goto free_clk;