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media: stm32-dcmi: fix DMA corruption when stopping streaming

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Avoid call of dmaengine_terminate_all() between
dmaengine_prep_slave_single() and dmaengine_submit() by locking
the whole DMA submission sequence.

Signed-off-by: Hugues Fruchet <hugues.fruchet@st.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
This commit is contained in:
Hugues Fruchet
2019-02-28 12:10:53 -05:00
committed by Mauro Carvalho Chehab
parent ab41b99e7e
commit b3ce6f6ff3
1 changed files with 17 additions and 0 deletions
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17
drivers/media/platform/stm32/stm32-dcmi.c
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@@ -164,6 +164,9 @@ struct stm32_dcmi {
int errors_count; int errors_count;
int overrun_count; int overrun_count;
int buffers_count; int buffers_count;
/* Ensure DMA operations atomicity */
struct mutex dma_lock;
}; };
static inline struct stm32_dcmi *notifier_to_dcmi(struct v4l2_async_notifier *n) static inline struct stm32_dcmi *notifier_to_dcmi(struct v4l2_async_notifier *n)
@@ -314,6 +317,13 @@ static int dcmi_start_dma(struct stm32_dcmi *dcmi,
return ret; return ret;
} }
/*
* Avoid call of dmaengine_terminate_all() between
* dmaengine_prep_slave_single() and dmaengine_submit()
* by locking the whole DMA submission sequence
*/
mutex_lock(&dcmi->dma_lock);
/* Prepare a DMA transaction */ /* Prepare a DMA transaction */
desc = dmaengine_prep_slave_single(dcmi->dma_chan, buf->paddr, desc = dmaengine_prep_slave_single(dcmi->dma_chan, buf->paddr,
buf->size, buf->size,
@@ -322,6 +332,7 @@ static int dcmi_start_dma(struct stm32_dcmi *dcmi,
if (!desc) { if (!desc) {
dev_err(dcmi->dev, "%s: DMA dmaengine_prep_slave_single failed for buffer phy=%pad size=%zu\n", dev_err(dcmi->dev, "%s: DMA dmaengine_prep_slave_single failed for buffer phy=%pad size=%zu\n",
__func__, &buf->paddr, buf->size); __func__, &buf->paddr, buf->size);
mutex_unlock(&dcmi->dma_lock);
return -EINVAL; return -EINVAL;
} }
@@ -333,9 +344,12 @@ static int dcmi_start_dma(struct stm32_dcmi *dcmi,
dcmi->dma_cookie = dmaengine_submit(desc); dcmi->dma_cookie = dmaengine_submit(desc);
if (dma_submit_error(dcmi->dma_cookie)) { if (dma_submit_error(dcmi->dma_cookie)) {
dev_err(dcmi->dev, "%s: DMA submission failed\n", __func__); dev_err(dcmi->dev, "%s: DMA submission failed\n", __func__);
mutex_unlock(&dcmi->dma_lock);
return -ENXIO; return -ENXIO;
} }
mutex_unlock(&dcmi->dma_lock);
dma_async_issue_pending(dcmi->dma_chan); dma_async_issue_pending(dcmi->dma_chan);
return 0; return 0;
@@ -720,7 +734,9 @@ static void dcmi_stop_streaming(struct vb2_queue *vq)
spin_unlock_irq(&dcmi->irqlock); spin_unlock_irq(&dcmi->irqlock);
/* Stop all pending DMA operations */ /* Stop all pending DMA operations */
mutex_lock(&dcmi->dma_lock);
dmaengine_terminate_all(dcmi->dma_chan); dmaengine_terminate_all(dcmi->dma_chan);
mutex_unlock(&dcmi->dma_lock);
pm_runtime_put(dcmi->dev); pm_runtime_put(dcmi->dev);
@@ -1711,6 +1727,7 @@ static int dcmi_probe(struct platform_device *pdev)
spin_lock_init(&dcmi->irqlock); spin_lock_init(&dcmi->irqlock);
mutex_init(&dcmi->lock); mutex_init(&dcmi->lock);
mutex_init(&dcmi->dma_lock);
init_completion(&dcmi->complete); init_completion(&dcmi->complete);
INIT_LIST_HEAD(&dcmi->buffers); INIT_LIST_HEAD(&dcmi->buffers);