[PATCH 5.10 186/236] mmc: sdhci: Fix issue with uninitialized dma_slave_config

[Greg Kroah-Hartman]

From: Tony Lindgren <tony@xxxxxxxxxxx>

[ Upstream commit 522654d534d315d540710124c57b49ca22ac5f72 ]

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 at least if external TI SDMA is ever configured for sdhci.

For other external DMA cases, this is probably not currently an issue but
is still good to fix though.

Fixes: 18e762e3b7a7 ("mmc: sdhci: add support for using external DMA devices")
Cc: Adrian Hunter <adrian.hunter@xxxxxxxxx>
Cc: Chunyan Zhang <zhang.chunyan@xxxxxxxxxx>
Cc: Faiz Abbas <faiz_abbas@xxxxxx>
Cc: Peter Ujfalusi <peter.ujfalusi@xxxxxxxxx>
Cc: Vinod Koul <vkoul@xxxxxxxxxx>
Signed-off-by: Tony Lindgren <tony@xxxxxxxxxxx>
Acked-by: Adrian Hunter <adrian.hunter@xxxxxxxxx>
Reviewed-by: Peter Ujfalusi <peter.ujfalusi@xxxxxxxxx>
Link: https://lore.kernel.org/r/20210810081644.19353-1-tony@xxxxxxxxxxx
Signed-off-by: Ulf Hansson <ulf.hansson@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 drivers/mmc/host/sdhci.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
index 6cdadbb3accd..b1e1d327cb8e 100644
--- a/drivers/mmc/host/sdhci.c
+++ b/drivers/mmc/host/sdhci.c
@@ -1223,6 +1223,7 @@ static int sdhci_external_dma_setup(struct sdhci_host *host,
 	if (!host->mapbase)
 		return -EINVAL;
 
+	memset(&cfg, 0, sizeof(cfg));
 	cfg.src_addr = host->mapbase + SDHCI_BUFFER;
 	cfg.dst_addr = host->mapbase + SDHCI_BUFFER;
 	cfg.src_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
-- 
2.30.2