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Subject[08/34] mmc: atmel-mci: prevent kernel oops while removing card
2.6.34-stable review patch.  If anyone has any objections, please let us know.

------------------
From: Nicolas Ferre <nicolas.ferre@atmel.com>

commit 009a891b22395fc86e5f34057d79fffee4509ab5 upstream.

The removing of an SD card in certain circumstances can lead to a kernel
oops if we do not make sure that the "data" field of the host structure is
valid. This patch adds a test in atmci_dma_cleanup() function and also
calls atmci_stop_dma() before throwing away the reference to data.

Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Cc: Haavard Skinnemoen <hskinnemoen@atmel.com>
Cc: <linux-mmc@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

---
drivers/mmc/host/atmel-mci.c | 9 +++++----
1 file changed, 5 insertions(+), 4 deletions(-)
--- a/drivers/mmc/host/atmel-mci.c
+++ b/drivers/mmc/host/atmel-mci.c
@@ -530,9 +530,10 @@ static void atmci_dma_cleanup(struct atm
{
struct mmc_data *data = host->data;

- dma_unmap_sg(&host->pdev->dev, data->sg, data->sg_len,
- ((data->flags & MMC_DATA_WRITE)
- ? DMA_TO_DEVICE : DMA_FROM_DEVICE));
+ if (data)
+ dma_unmap_sg(&host->pdev->dev, data->sg, data->sg_len,
+ ((data->flags & MMC_DATA_WRITE)
+ ? DMA_TO_DEVICE : DMA_FROM_DEVICE));
}

static void atmci_stop_dma(struct atmel_mci *host)
@@ -1037,8 +1038,8 @@ static void atmci_command_complete(struc
"command error: status=0x%08x\n", status);

if (cmd->data) {
- host->data = NULL;
atmci_stop_dma(host);
+ host->data = NULL;
mci_writel(host, IDR, MCI_NOTBUSY
| MCI_TXRDY | MCI_RXRDY
| ATMCI_DATA_ERROR_FLAGS);



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