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Subject[PATCH] mmc: wbsd: safer check if dma_addr is valid DMA address
Date
host->dma_addr can store a value that is not returned by the DMA API,
so it is safer to check if is a valid DMA address indirectly.

Signed-off-by: Alexey Khoroshilov <khoroshilov@ispras.ru>
---
drivers/mmc/host/wbsd.c | 7 +++++--
1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/drivers/mmc/host/wbsd.c b/drivers/mmc/host/wbsd.c
index 80a3b11f3217..bd04e8bae010 100644
--- a/drivers/mmc/host/wbsd.c
+++ b/drivers/mmc/host/wbsd.c
@@ -1437,11 +1437,14 @@ static void wbsd_request_dma(struct wbsd_host *host, int dma)

static void wbsd_release_dma(struct wbsd_host *host)
{
- if (!dma_mapping_error(mmc_dev(host->mmc), host->dma_addr)) {
+ /*
+ * host->dma_addr is valid here iff host->dma_buffer is not NULL.
+ */
+ if (host->dma_buffer) {
dma_unmap_single(mmc_dev(host->mmc), host->dma_addr,
WBSD_DMA_SIZE, DMA_BIDIRECTIONAL);
+ kfree(host->dma_buffer);
}
- kfree(host->dma_buffer);
if (host->dma >= 0)
free_dma(host->dma);

--
2.7.4
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