mmc: atmel-mci: prevent kernel oops while removing card

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>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Nicolas Ferre 2010-05-11 14:06:49 -07:00 committed by Linus Torvalds
parent ebb1fea9b3
commit 009a891b22
1 changed files with 5 additions and 4 deletions

View File

@ -569,9 +569,10 @@ static void atmci_dma_cleanup(struct atmel_mci *host)
{
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)
@ -1099,8 +1100,8 @@ static void atmci_command_complete(struct atmel_mci *host,
"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);