diff options
Diffstat (limited to 'drivers/media/platform/stm32/stm32-dcmi.c')
-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 4281f3f76ab1..f157ccbd8286 100644 --- a/drivers/media/platform/stm32/stm32-dcmi.c +++ b/drivers/media/platform/stm32/stm32-dcmi.c @@ -161,6 +161,9 @@ struct stm32_dcmi { u32 misr; int errors_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) @@ -291,6 +294,13 @@ 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, @@ -298,6 +308,7 @@ static int dcmi_start_dma(struct stm32_dcmi *dcmi, if (!desc) { dev_err(dcmi->dev, "%s: DMA dmaengine_prep_slave_single failed for buffer size %zu\n", __func__, buf->size); + mutex_unlock(&dcmi->dma_lock); return -EINVAL; } @@ -309,9 +320,12 @@ 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; @@ -690,7 +704,9 @@ 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); clk_disable(dcmi->mclk); @@ -1662,6 +1678,7 @@ 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); |