Re: [PATCH] Fix Oops with Atmel SPI

From: Anders Larsen
Date: Wed May 19 2010 - 07:05:27 EST


On 2010-04-22 00:24:10, Andrew Morton wrote:
> Finally.. Wouldn't it be better to just fix the atmel SPI driver so
> that it doesn't barf when handed vmalloc'ed memory? Who do we ridicule
> about that? <checks, adds cc>

You mean something like this instead?

diff --git a/drivers/spi/atmel_spi.c b/drivers/spi/atmel_spi.c
index c4e0442..a9ad5e8 100644
--- a/drivers/spi/atmel_spi.c
+++ b/drivers/spi/atmel_spi.c
@@ -352,16 +352,30 @@ atmel_spi_dma_map_xfer(struct atmel_spi *as, struct spi_transfer *xfer)

xfer->tx_dma = xfer->rx_dma = INVALID_DMA_ADDRESS;
if (xfer->tx_buf) {
- xfer->tx_dma = dma_map_single(dev,
- (void *) xfer->tx_buf, xfer->len,
- DMA_TO_DEVICE);
+ if (is_vmalloc_addr(xfer->tx_buf))
+ xfer->tx_dma = dma_map_page(dev,
+ vmalloc_to_page(xfer->tx_buf),
+ (unsigned long)xfer->tx_buf & (PAGE_SIZE-1),
+ xfer->len,
+ DMA_TO_DEVICE);
+ else
+ xfer->tx_dma = dma_map_single(dev,
+ (void *) xfer->tx_buf, xfer->len,
+ DMA_TO_DEVICE);
if (dma_mapping_error(dev, xfer->tx_dma))
return -ENOMEM;
}
if (xfer->rx_buf) {
- xfer->rx_dma = dma_map_single(dev,
- xfer->rx_buf, xfer->len,
- DMA_FROM_DEVICE);
+ if (is_vmalloc_addr(xfer->rx_buf))
+ xfer->rx_dma = dma_map_page(dev,
+ vmalloc_to_page(xfer->rx_buf),
+ (unsigned long)xfer->rx_buf & (PAGE_SIZE-1),
+ xfer->len,
+ DMA_FROM_DEVICE);
+ else
+ xfer->rx_dma = dma_map_single(dev,
+ xfer->rx_buf, xfer->len,
+ DMA_FROM_DEVICE);
if (dma_mapping_error(dev, xfer->rx_dma)) {
if (xfer->tx_buf)
dma_unmap_single(dev,

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