Messages in this thread Patch in this message | | | From | Alexey Khoroshilov <> | Subject | [PATCH] mmc: wbsd: safer check if dma_addr is valid DMA address | Date | Sat, 14 Jan 2017 01:52:51 +0300 |
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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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