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List:       linux-mmc
Subject:    [PATCH 1/3] mmc: tmio-mmc: add DMA SG synchronisation
From:       Guennadi Liakhovetski <g.liakhovetski () gmx ! de>
Date:       2014-01-31 11:54:19
Message-ID: Pine.LNX.4.64.1401311248320.3234 () axis700 ! grange
[Download RAW message or body]

According to the DMA API data has to be synchronised before starting
a DMA transfer to device and after completing a DMA transfer from device.

Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
---
 drivers/mmc/host/tmio_mmc_dma.c |   21 ++++++++++++---------
 1 files changed, 12 insertions(+), 9 deletions(-)

diff --git a/drivers/mmc/host/tmio_mmc_dma.c b/drivers/mmc/host/tmio_mmc_dma.c
index 65edb4a..a997b94 100644
--- a/drivers/mmc/host/tmio_mmc_dma.c
+++ b/drivers/mmc/host/tmio_mmc_dma.c
@@ -168,9 +168,12 @@ static void tmio_mmc_start_dma_tx(struct tmio_mmc_host *host)
 	}
 
 	ret = dma_map_sg(chan->device->dev, sg, host->sg_len, DMA_TO_DEVICE);
-	if (ret > 0)
+	if (ret > 0) {
+		dma_sync_sg_for_device(chan->device->dev, sg, host->sg_len,
+				       DMA_TO_DEVICE);
 		desc = dmaengine_prep_slave_sg(chan, sg, ret,
 			DMA_MEM_TO_DEV, DMA_CTRL_ACK);
+	}
 
 	if (desc) {
 		cookie = dmaengine_submit(desc);
@@ -247,14 +250,14 @@ static void tmio_mmc_tasklet_fn(unsigned long arg)
 	if (!host->data)
 		goto out;
 
-	if (host->data->flags & MMC_DATA_READ)
-		dma_unmap_sg(host->chan_rx->device->dev,
-			     host->sg_ptr, host->sg_len,
-			     DMA_FROM_DEVICE);
-	else
-		dma_unmap_sg(host->chan_tx->device->dev,
-			     host->sg_ptr, host->sg_len,
-			     DMA_TO_DEVICE);
+	if (host->data->flags & MMC_DATA_READ) {
+		struct device *dev = host->chan_rx->device->dev;
+		dma_unmap_sg(dev, host->sg_ptr, host->sg_len, DMA_FROM_DEVICE);
+		dma_sync_sg_for_cpu(dev, host->sg_ptr, host->sg_len, DMA_FROM_DEVICE);
+	} else {
+		struct device *dev = host->chan_tx->device->dev;
+		dma_unmap_sg(dev, host->sg_ptr, host->sg_len, DMA_TO_DEVICE);
+	}
 
 	tmio_mmc_do_data_irq(host);
 out:
-- 
1.7.2.5

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