Depending on the DMA driver being used, the struct dma_slave_config may need to be initialized to zero for the unused data. For example, we have three DMA drivers using src_port_window_size and dst_port_window_size. If these are left uninitialized, it can cause DMA failures. For dw_mmc, this is probably not currently an issue but is still good to fix though. Fixes: 3fc7eaef44db ("mmc: dw_mmc: Add external dma interface support") Cc: Shawn Lin <shawn.lin@xxxxxxxxxxxxxx> Cc: Jaehoon Chung <jh80.chung@xxxxxxxxxxx> Cc: Peter Ujfalusi <peter.ujfalusi@xxxxxxxxx> Cc: Vinod Koul <vkoul@xxxxxxxxxx> Signed-off-by: Tony Lindgren <tony@xxxxxxxxxxx> --- drivers/mmc/host/dw_mmc.c | 1 + 1 file changed, 1 insertion(+) diff --git a/drivers/mmc/host/dw_mmc.c b/drivers/mmc/host/dw_mmc.c --- a/drivers/mmc/host/dw_mmc.c +++ b/drivers/mmc/host/dw_mmc.c @@ -782,6 +782,7 @@ static int dw_mci_edmac_start_dma(struct dw_mci *host, int ret = 0; /* Set external dma config: burst size, burst width */ + memset(&cfg, 0, sizeof(cfg)); cfg.dst_addr = host->phy_regs + fifo_offset; cfg.src_addr = cfg.dst_addr; cfg.dst_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES; -- 2.32.0