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>
diff --git a/drivers/mmc/host/atmel-mci.c b/drivers/mmc/host/atmel-mci.c
index 57d3cb2d..2a5d5ca 100644
--- a/drivers/mmc/host/atmel-mci.c
+++ b/drivers/mmc/host/atmel-mci.c
@@ -569,9 +569,10 @@
{
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 @@
"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);