From 009a891b22395fc86e5f34057d79fffee4509ab5 Mon Sep 17 00:00:00 2001 From: Nicolas Ferre Date: Tue, 11 May 2010 14:06:49 -0700 Subject: [PATCH] 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 Cc: Haavard Skinnemoen Cc: Cc: Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- drivers/mmc/host/atmel-mci.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/drivers/mmc/host/atmel-mci.c b/drivers/mmc/host/atmel-mci.c index 57d3cb2dbb5f..2a5d5cafeb5f 100644 --- a/drivers/mmc/host/atmel-mci.c +++ b/drivers/mmc/host/atmel-mci.c @@ -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); -- 2.20.1