From 6dc6f2619017109e45550accc120f823fdc31c3e Mon Sep 17 00:00:00 2001
From: Stefan Wahren <stefan.wahren@i2se.com>
Date: Sun, 11 Nov 2018 21:23:58 +0100
Subject: [PATCH] mmc: bcm2835: Refactor dma_map_sg handling

There are two variables len within bcm2835_prepare_dma. So rename the
result of dma_map_sg to sg_len. While we are at this add a bail out to
simplify the following change.

Signed-off-by: Stefan Wahren <stefan.wahren@i2se.com>
Acked-by: Eric Anholt <eric@anholt.net>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
---
 drivers/mmc/host/bcm2835.c | 16 +++++++---------
 1 file changed, 7 insertions(+), 9 deletions(-)

diff --git a/drivers/mmc/host/bcm2835.c b/drivers/mmc/host/bcm2835.c
index a7961c391de69..7733dbd57073a 100644
--- a/drivers/mmc/host/bcm2835.c
+++ b/drivers/mmc/host/bcm2835.c
@@ -453,7 +453,7 @@ static void bcm2835_transfer_pio(struct bcm2835_host *host)
 static
 void bcm2835_prepare_dma(struct bcm2835_host *host, struct mmc_data *data)
 {
-	int len, dir_data, dir_slave;
+	int sg_len, dir_data, dir_slave;
 	struct dma_async_tx_descriptor *desc = NULL;
 	struct dma_chan *dma_chan;
 
@@ -499,15 +499,13 @@ void bcm2835_prepare_dma(struct bcm2835_host *host, struct mmc_data *data)
 				     &host->dma_cfg_rx :
 				     &host->dma_cfg_tx);
 
-	len = dma_map_sg(dma_chan->device->dev, data->sg, data->sg_len,
-			 dir_data);
+	sg_len = dma_map_sg(dma_chan->device->dev, data->sg, data->sg_len,
+			    dir_data);
+	if (!sg_len)
+		return;
 
-	if (len > 0) {
-		desc = dmaengine_prep_slave_sg(dma_chan, data->sg,
-					       len, dir_slave,
-					       DMA_PREP_INTERRUPT |
-					       DMA_CTRL_ACK);
-	}
+	desc = dmaengine_prep_slave_sg(dma_chan, data->sg, sg_len, dir_slave,
+				       DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
 
 	if (desc) {
 		desc->callback = bcm2835_dma_complete;
-- 
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