[PATCH v2] mmc: omap: Initialize dma_slave_config to avoid random data in it's fields

From: Peter Ujfalusi
Date: Wed Sep 14 2016 - 07:22:11 EST


It is wrong to use uninitialized dma_slave_config and configure only
certain fields as the DMAengine driver might look at non initialized
(random data) fields and tries to interpret it.

Signed-off-by: Peter Ujfalusi <peter.ujfalusi@xxxxxx>
---
Hi,

Changes since v1:
- do the field initialization in one step

would it be possible to send this patch for 4.8? I have omap-dma DMAengine
driver changes pending, but they break the MMC/SD because of the uninitialized
fields in dma_slave_config.

Thanks,
Peter

drivers/mmc/host/omap.c | 18 ++++++++++--------
1 file changed, 10 insertions(+), 8 deletions(-)

diff --git a/drivers/mmc/host/omap.c b/drivers/mmc/host/omap.c
index f23d65eb070d..be3c49fa7382 100644
--- a/drivers/mmc/host/omap.c
+++ b/drivers/mmc/host/omap.c
@@ -1016,14 +1016,16 @@ mmc_omap_prepare_data(struct mmc_omap_host *host, struct mmc_request *req)

/* Only reconfigure if we have a different burst size */
if (*bp != burst) {
- struct dma_slave_config cfg;
-
- cfg.src_addr = host->phys_base + OMAP_MMC_REG(host, DATA);
- cfg.dst_addr = host->phys_base + OMAP_MMC_REG(host, DATA);
- cfg.src_addr_width = DMA_SLAVE_BUSWIDTH_2_BYTES;
- cfg.dst_addr_width = DMA_SLAVE_BUSWIDTH_2_BYTES;
- cfg.src_maxburst = burst;
- cfg.dst_maxburst = burst;
+ struct dma_slave_config cfg = {
+ .src_addr = host->phys_base +
+ OMAP_MMC_REG(host, DATA),
+ .dst_addr = host->phys_base +
+ OMAP_MMC_REG(host, DATA),
+ .src_addr_width = DMA_SLAVE_BUSWIDTH_2_BYTES,
+ .dst_addr_width = DMA_SLAVE_BUSWIDTH_2_BYTES,
+ .src_maxburst = burst,
+ .dst_maxburst = burst,
+ };

if (dmaengine_slave_config(c, &cfg))
goto use_pio;
--
2.10.0