mmc: sh_mmcif: reset DMA completion immediately before starting DMA

DMA completion can be signalled from the DMA callback and from the error
handler. If both are called, the completion struct can enter an
inconsistent state. To prevent this move completion initialisation
immediately before activating DMA.
Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Chris Ball <cjb@laptop.org>

drivers/mmc/host/sh_mmcif.c

@@ -419,8 +419,6 @@ static void sh_mmcif_request_dma(struct sh_mmcif_host *host,
 	if (ret < 0)
 		goto ecfgrx;
 
-	init_completion(&host->dma_complete);
-
 	return;
 
 ecfgrx:
@@ -1061,6 +1059,12 @@ static bool sh_mmcif_end_cmd(struct sh_mmcif_host *host)
 	if (!data)
 		return false;
 
+	/*
+	 * Completion can be signalled from DMA callback and error, so, have to
+	 * reset here, before setting .dma_active
+	 */
+	init_completion(&host->dma_complete);
+
 	if (data->flags & MMC_DATA_READ) {
 		if (host->chan_rx)
 			sh_mmcif_start_dma_rx(host);