[PATCH AUTOSEL for 4.9 195/219] dmaengine: bcm2835-dma: Use vchan_terminate_vdesc() instead of desc_free

Sasha Levin
2018-03-03T23:27:05Z

From: Peter Ujfalusi <peter.ujfalusi@ti.com>

[ Upstream commit de92436ac40ffe9933230aa503e24dbb5ede9201 ]

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.

Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
Acked-by: Eric Anholt <eric@anholt.net>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
---
drivers/dma/bcm2835-dma.c | 10 +++++++++-
1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/drivers/dma/bcm2835-dma.c b/drivers/dma/bcm2835-dma.c
index 6204cc32d09c..847f84a41a69 100644
--- a/drivers/dma/bcm2835-dma.c
+++ b/drivers/dma/bcm2835-dma.c
@@ -812,7 +812,7 @@ static int bcm2835_dma_terminate_all(struct dma_chan *chan)
* c->desc is NULL and exit.)
*/
if (c->desc) {
- bcm2835_dma_desc_free(&c->desc->vd);
+ vchan_terminate_vdesc(&c->desc->vd);
c->desc = NULL;
bcm2835_dma_abort(c->chan_base);

@@ -836,6 +836,13 @@ static int bcm2835_dma_terminate_all(struct dma_chan *chan)
return 0;
}

+static void bcm2835_dma_synchronize(struct dma_chan *chan)
+{
+ struct bcm2835_chan *c = to_bcm2835_dma_chan(chan);
+
+ vchan_synchronize(&c->vc);
+}
+
static int bcm2835_dma_chan_init(struct bcm2835_dmadev *d, int chan_id,
int irq, unsigned int irq_flags)
{
@@ -942,6 +949,7 @@ static int bcm2835_dma_probe(struct platform_device *pdev)
od->ddev.device_prep_dma_memcpy = bcm2835_dma_prep_dma_memcpy;
od->ddev.device_config = bcm2835_dma_slave_config;
od->ddev.device_terminate_all = bcm2835_dma_terminate_all;
+ od->ddev.device_synchronize = bcm2835_dma_synchronize;
od->ddev.src_addr_widths = BIT(DMA_SLAVE_BUSWIDTH_4_BYTES);
od->ddev.dst_addr_widths = BIT(DMA_SLAVE_BUSWIDTH_4_BYTES);
od->ddev.directions = BIT(DMA_DEV_TO_MEM) | BIT(DMA_MEM_TO_DEV) |
--
2.14.1