The patch titled
spi_imx: full duplex dma corruption bugfix
has been added to the -mm tree. Its filename is
spi_imx-full-duplex-dma-corruption-bugfix.patch
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The current -mm tree may be found at http://userweb.kernel.org/~akpm/mmotm/
------------------------------------------------------
Subject: spi_imx: full duplex dma corruption bugfix
From: Andrea Paterniani <a.paterniani@xxxxxxxxxxxx>
Fix unsafe order in dma mapping operation: always flush data from the
cache *BEFORE* invalidating it, to allow full duplex transfers where the
same buffer may be used for both writes and reads.
Signed-off-by: Andrea Paterniani <a.paterniani@xxxxxxxxxxxx>
Signed-off-by: David Brownell <dbrownell@xxxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
drivers/spi/spi_imx.c | 45 +++++++++++++++++++---------------------
1 file changed, 22 insertions(+), 23 deletions(-)
diff -puN drivers/spi/spi_imx.c~spi_imx-full-duplex-dma-corruption-bugfix drivers/spi/spi_imx.c
--- a/drivers/spi/spi_imx.c~spi_imx-full-duplex-dma-corruption-bugfix
+++ a/drivers/spi/spi_imx.c
@@ -506,20 +506,6 @@ static int map_dma_buffers(struct driver
if (!IS_DMA_ALIGNED(drv_data->rx) || !IS_DMA_ALIGNED(drv_data->tx))
return -1;
- /* NULL rx means write-only transfer and no map needed
- since rx DMA will not be used */
- if (drv_data->rx) {
- buf = drv_data->rx;
- drv_data->rx_dma = dma_map_single(
- dev,
- buf,
- drv_data->len,
- DMA_FROM_DEVICE);
- if (dma_mapping_error(dev, drv_data->rx_dma))
- return -1;
- drv_data->rx_dma_needs_unmap = 1;
- }
-
if (drv_data->tx == NULL) {
/* Read only message --> use drv_data->dummy_dma_buf for dummy
writes to achive reads */
@@ -533,18 +519,31 @@ static int map_dma_buffers(struct driver
buf,
drv_data->tx_map_len,
DMA_TO_DEVICE);
- if (dma_mapping_error(dev, drv_data->tx_dma)) {
- if (drv_data->rx_dma) {
- dma_unmap_single(dev,
- drv_data->rx_dma,
- drv_data->len,
- DMA_FROM_DEVICE);
- drv_data->rx_dma_needs_unmap = 0;
- }
+ if (dma_mapping_error(dev, drv_data->tx_dma))
return -1;
- }
drv_data->tx_dma_needs_unmap = 1;
+ /* NULL rx means write-only transfer and no map needed
+ * since rx DMA will not be used */
+ if (drv_data->rx) {
+ buf = drv_data->rx;
+ drv_data->rx_dma = dma_map_single(dev,
+ buf,
+ drv_data->len,
+ DMA_FROM_DEVICE);
+ if (dma_mapping_error(dev, drv_data->rx_dma)) {
+ if (drv_data->tx_dma) {
+ dma_unmap_single(dev,
+ drv_data->tx_dma,
+ drv_data->tx_map_len,
+ DMA_TO_DEVICE);
+ drv_data->tx_dma_needs_unmap = 0;
+ }
+ return -1;
+ }
+ drv_data->rx_dma_needs_unmap = 1;
+ }
+
return 0;
}
_
Patches currently in -mm which might be from a.paterniani@xxxxxxxxxxxx are
spi_imx-full-duplex-dma-corruption-bugfix.patch
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