diff options
| author | Hugues Fruchet <hugues.fruchet@st.com> | 2019-02-28 12:10:53 -0500 |
|---|---|---|
| committer | Mauro Carvalho Chehab <mchehab+samsung@kernel.org> | 2019-03-19 13:50:08 -0400 |
| commit | b3ce6f6ff3c260ee53b0f2236e5fd950d46957da (patch) | |
| tree | d2d5840813fe258618aecfc250ce2c7eb7ccf74b /drivers | |
| parent | ab41b99e7e55c85f29ff7b54718ccbbe051905e7 (diff) | |
media: stm32-dcmi: fix DMA corruption when stopping streaming
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>
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/media/platform/stm32/stm32-dcmi.c | 17 |
1 files changed, 17 insertions, 0 deletions
diff --git a/drivers/media/platform/stm32/stm32-dcmi.c b/drivers/media/platform/stm32/stm32-dcmi.c index 37e9fb08918a..098431d927ac 100644 --- a/drivers/media/platform/stm32/stm32-dcmi.c +++ b/drivers/media/platform/stm32/stm32-dcmi.c @@ -164,6 +164,9 @@ struct stm32_dcmi { int errors_count; int overrun_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) @@ -314,6 +317,13 @@ static int dcmi_start_dma(struct stm32_dcmi *dcmi, 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 */ desc = dmaengine_prep_slave_single(dcmi->dma_chan, buf->paddr, buf->size, @@ -322,6 +332,7 @@ static int dcmi_start_dma(struct stm32_dcmi *dcmi, if (!desc) { dev_err(dcmi->dev, "%s: DMA dmaengine_prep_slave_single failed for buffer phy=%pad size=%zu\n", __func__, &buf->paddr, buf->size); + mutex_unlock(&dcmi->dma_lock); return -EINVAL; } @@ -333,9 +344,12 @@ static int dcmi_start_dma(struct stm32_dcmi *dcmi, dcmi->dma_cookie = dmaengine_submit(desc); if (dma_submit_error(dcmi->dma_cookie)) { dev_err(dcmi->dev, "%s: DMA submission failed\n", __func__); + mutex_unlock(&dcmi->dma_lock); return -ENXIO; } + mutex_unlock(&dcmi->dma_lock); + dma_async_issue_pending(dcmi->dma_chan); return 0; @@ -720,7 +734,9 @@ static void dcmi_stop_streaming(struct vb2_queue *vq) spin_unlock_irq(&dcmi->irqlock); /* Stop all pending DMA operations */ + mutex_lock(&dcmi->dma_lock); dmaengine_terminate_all(dcmi->dma_chan); + mutex_unlock(&dcmi->dma_lock); pm_runtime_put(dcmi->dev); @@ -1711,6 +1727,7 @@ static int dcmi_probe(struct platform_device *pdev) spin_lock_init(&dcmi->irqlock); mutex_init(&dcmi->lock); + mutex_init(&dcmi->dma_lock); init_completion(&dcmi->complete); INIT_LIST_HEAD(&dcmi->buffers); |