[PATCH 10/10] dmaengine: s3c24xx-dma: Use vchan_terminate_vdesc() instead of desc_free

From: Peter Ujfalusi
Date: Tue Nov 14 2017 - 09:34:53 EST


To avoid race with vchan_complete, use the race free way to terminate
running transfer.

Implement the device_synchronize callback to make sure that the terminated
descriptor is freed.

CC: Krzysztof Kozlowski <krzk@xxxxxxxxxx>
Signed-off-by: Peter Ujfalusi <peter.ujfalusi@xxxxxx>
---
drivers/dma/s3c24xx-dma.c | 11 ++++++++++-
1 file changed, 10 insertions(+), 1 deletion(-)

diff --git a/drivers/dma/s3c24xx-dma.c b/drivers/dma/s3c24xx-dma.c
index f04c4702d98b..cd92d696bcf9 100644
--- a/drivers/dma/s3c24xx-dma.c
+++ b/drivers/dma/s3c24xx-dma.c
@@ -732,7 +732,7 @@ static int s3c24xx_dma_terminate_all(struct dma_chan *chan)

/* Dequeue current job */
if (s3cchan->at) {
- s3c24xx_dma_desc_free(&s3cchan->at->vd);
+ vchan_terminate_vdesc(&s3cchan->at->vd);
s3cchan->at = NULL;
}

@@ -744,6 +744,13 @@ static int s3c24xx_dma_terminate_all(struct dma_chan *chan)
return ret;
}

+static void s3c24xx_dma_synchronize(struct dma_chan *chan)
+{
+ struct s3c24xx_dma_chan *s3cchan = to_s3c24xx_dma_chan(chan);
+
+ vchan_synchronize(&s3cchan->vc);
+}
+
static void s3c24xx_dma_free_chan_resources(struct dma_chan *chan)
{
/* Ensure all queued descriptors are freed */
@@ -1282,6 +1289,7 @@ static int s3c24xx_dma_probe(struct platform_device *pdev)
s3cdma->memcpy.device_issue_pending = s3c24xx_dma_issue_pending;
s3cdma->memcpy.device_config = s3c24xx_dma_set_runtime_config;
s3cdma->memcpy.device_terminate_all = s3c24xx_dma_terminate_all;
+ s3cdma->memcpy.device_synchronize = s3c24xx_dma_synchronize;

/* Initialize slave engine for SoC internal dedicated peripherals */
dma_cap_set(DMA_SLAVE, s3cdma->slave.cap_mask);
@@ -1296,6 +1304,7 @@ static int s3c24xx_dma_probe(struct platform_device *pdev)
s3cdma->slave.device_prep_dma_cyclic = s3c24xx_dma_prep_dma_cyclic;
s3cdma->slave.device_config = s3c24xx_dma_set_runtime_config;
s3cdma->slave.device_terminate_all = s3c24xx_dma_terminate_all;
+ s3cdma->slave.device_synchronize = s3c24xx_dma_synchronize;
s3cdma->slave.filter.map = pdata->slave_map;
s3cdma->slave.filter.mapcnt = pdata->slavecnt;
s3cdma->slave.filter.fn = s3c24xx_dma_filter;
--
Peter

Texas Instruments Finland Oy, Porkkalankatu 22, 00180 Helsinki.
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