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authorHaavard Skinnemoen <hskinnemoen@atmel.com>2008-02-06 01:38:13 -0800
committerLinus Torvalds <torvalds@woody.linux-foundation.org>2008-02-06 10:41:10 -0800
commit8bacb219018a52e6f02a3cff6a7badf102ddfc44 (patch)
tree7e89a0346ce1694c32cf035c2badb2ff77db6a00 /drivers
parent154443c72f47169ebcb3a7befbff0e934c49bff3 (diff)
atmel_spi: fix dmachain oops with DEBUG enabled
In atmel_spi_next_xfer, xfer can be NULL because the next transfer may already have been submitted to the PDC (using DMA chaining). This can cause an oops, since the debug message assumed it was never null. The fix changes how those debug messages are issued, ensuring that one is issued each time a transfer is started instead of once per call. Also, properly indent the "can this transfer be chained" test so it's not hidden as if it were non-conditional code. Signed-off-by: Haavard Skinnemoen <hskinnemoen@atmel.com> Signed-off-by: David Brownell <dbrownell@users.sourceforge.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'drivers')
-rw-r--r--drivers/spi/atmel_spi.c20
1 files changed, 12 insertions, 8 deletions
diff --git a/drivers/spi/atmel_spi.c b/drivers/spi/atmel_spi.c
index 545519a063b..293b7cab3e5 100644
--- a/drivers/spi/atmel_spi.c
+++ b/drivers/spi/atmel_spi.c
@@ -198,6 +198,11 @@ static void atmel_spi_next_xfer(struct spi_master *master,
len >>= 1;
spi_writel(as, RCR, len);
spi_writel(as, TCR, len);
+
+ dev_dbg(&msg->spi->dev,
+ " start xfer %p: len %u tx %p/%08x rx %p/%08x\n",
+ xfer, xfer->len, xfer->tx_buf, xfer->tx_dma,
+ xfer->rx_buf, xfer->rx_dma);
} else {
xfer = as->next_transfer;
remaining = as->next_remaining_bytes;
@@ -208,8 +213,8 @@ static void atmel_spi_next_xfer(struct spi_master *master,
if (remaining > 0)
len = remaining;
- else if (!atmel_spi_xfer_is_last(msg, xfer) &&
- atmel_spi_xfer_can_be_chained(xfer)) {
+ else if (!atmel_spi_xfer_is_last(msg, xfer)
+ && atmel_spi_xfer_can_be_chained(xfer)) {
xfer = list_entry(xfer->transfer_list.next,
struct spi_transfer, transfer_list);
len = xfer->len;
@@ -230,6 +235,11 @@ static void atmel_spi_next_xfer(struct spi_master *master,
len >>= 1;
spi_writel(as, RNCR, len);
spi_writel(as, TNCR, len);
+
+ dev_dbg(&msg->spi->dev,
+ " next xfer %p: len %u tx %p/%08x rx %p/%08x\n",
+ xfer, xfer->len, xfer->tx_buf, xfer->tx_dma,
+ xfer->rx_buf, xfer->rx_dma);
} else {
spi_writel(as, RNCR, 0);
spi_writel(as, TNCR, 0);
@@ -246,12 +256,6 @@ static void atmel_spi_next_xfer(struct spi_master *master,
* It should be doable, though. Just not now...
*/
spi_writel(as, IER, SPI_BIT(ENDRX) | SPI_BIT(OVRES));
-
- dev_dbg(&msg->spi->dev,
- " start xfer %p: len %u tx %p/%08x rx %p/%08x imr %03x\n",
- xfer, xfer->len, xfer->tx_buf, xfer->tx_dma,
- xfer->rx_buf, xfer->rx_dma, spi_readl(as, IMR));
-
spi_writel(as, PTCR, SPI_BIT(TXTEN) | SPI_BIT(RXTEN));
}