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media: stm32-dcmi: revisit buffer list management

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Cleanup "active" field usage and enhance list management
to avoid exceptions when releasing buffers on error or
stopping streaming.

Signed-off-by: Hugues Fruchet <hugues.fruchet@st.com>
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
This commit is contained in:
Hugues Fruchet 2018-06-11 05:50:27 -04:00 committed by Mauro Carvalho Chehab
parent 2d494d4a09
commit 49bcc1746f
1 changed files with 31 additions and 34 deletions
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65
drivers/media/platform/stm32/stm32-dcmi.c
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@ -190,7 +190,7 @@ static inline void reg_clear(void __iomem *base, u32 reg, u32 mask)
reg_write(base, reg, reg_read(base, reg) & ~mask);
}
static int dcmi_start_capture(struct stm32_dcmi *dcmi);
static int dcmi_start_capture(struct stm32_dcmi *dcmi, struct dcmi_buf *buf);
static void dcmi_buffer_done(struct stm32_dcmi *dcmi,
struct dcmi_buf *buf,
@ -202,6 +202,8 @@ static void dcmi_buffer_done(struct stm32_dcmi *dcmi,
if (!buf)
return;
list_del_init(&buf->list);
vbuf = &buf->vb;
vbuf->sequence = dcmi->sequence++;
@ -219,6 +221,8 @@ static void dcmi_buffer_done(struct stm32_dcmi *dcmi,
static int dcmi_restart_capture(struct stm32_dcmi *dcmi)
{
struct dcmi_buf *buf;
spin_lock_irq(&dcmi->irqlock);
if (dcmi->state != RUNNING) {
@ -229,19 +233,16 @@ static int dcmi_restart_capture(struct stm32_dcmi *dcmi)
/* Restart a new DMA transfer with next buffer */
if (list_empty(&dcmi->buffers)) {
dev_dbg(dcmi->dev, "Capture restart is deferred to next buffer queueing\n");
dcmi->active = NULL;
dcmi->state = WAIT_FOR_BUFFER;
spin_unlock_irq(&dcmi->irqlock);
return 0;
}
dcmi->active = list_entry(dcmi->buffers.next,
struct dcmi_buf, list);
list_del_init(&dcmi->active->list);
buf = list_entry(dcmi->buffers.next, struct dcmi_buf, list);
dcmi->active = buf;
spin_unlock_irq(&dcmi->irqlock);
return dcmi_start_capture(dcmi);
return dcmi_start_capture(dcmi, buf);
}
static void dcmi_dma_callback(void *param)
@ -251,6 +252,8 @@ static void dcmi_dma_callback(void *param)
enum dma_status status;
struct dcmi_buf *buf = dcmi->active;
spin_lock_irq(&dcmi->irqlock);
/* Check DMA status */
status = dmaengine_tx_status(dcmi->dma_chan, dcmi->dma_cookie, &state);
@ -273,15 +276,19 @@ static void dcmi_dma_callback(void *param)
/* Return buffer to V4L2 */
dcmi_buffer_done(dcmi, buf, buf->size, 0);
spin_unlock_irq(&dcmi->irqlock);
/* Restart capture */
if (dcmi_restart_capture(dcmi))
dev_err(dcmi->dev, "%s: Cannot restart capture on DMA complete\n",
__func__);
break;
return;
default:
dev_err(dcmi->dev, "%s: Received unknown status\n", __func__);
break;
}
spin_unlock_irq(&dcmi->irqlock);
}
static int dcmi_start_dma(struct stm32_dcmi *dcmi,
@ -333,10 +340,9 @@ static int dcmi_start_dma(struct stm32_dcmi *dcmi,
return 0;
}
static int dcmi_start_capture(struct stm32_dcmi *dcmi)
static int dcmi_start_capture(struct stm32_dcmi *dcmi, struct dcmi_buf *buf)
{
int ret;
struct dcmi_buf *buf = dcmi->active;
if (!buf)
return -EINVAL;
@ -490,8 +496,6 @@ static int dcmi_queue_setup(struct vb2_queue *vq,
*nplanes = 1;
sizes[0] = size;
dcmi->active = NULL;
dev_dbg(dcmi->dev, "Setup queue, count=%d, size=%d\n",
*nbuffers, size);
@ -549,23 +553,24 @@ static void dcmi_buf_queue(struct vb2_buffer *vb)
spin_lock_irq(&dcmi->irqlock);
dcmi->active = buf;
/* Enqueue to video buffers list */
list_add_tail(&buf->list, &dcmi->buffers);
if (dcmi->state == WAIT_FOR_BUFFER) {
dcmi->state = RUNNING;
dcmi->active = buf;
dev_dbg(dcmi->dev, "Starting capture on buffer[%d] queued\n",
buf->vb.vb2_buf.index);
spin_unlock_irq(&dcmi->irqlock);
if (dcmi_start_capture(dcmi))
if (dcmi_start_capture(dcmi, buf))
dev_err(dcmi->dev, "%s: Cannot restart capture on overflow or error\n",
__func__);
} else {
/* Enqueue to video buffers list */
list_add_tail(&buf->list, &dcmi->buffers);
spin_unlock_irq(&dcmi->irqlock);
return;
}
spin_unlock_irq(&dcmi->irqlock);
}
static int dcmi_start_streaming(struct vb2_queue *vq, unsigned int count)
@ -637,7 +642,6 @@ static int dcmi_start_streaming(struct vb2_queue *vq, unsigned int count)
dcmi->errors_count = 0;
dcmi->overrun_count = 0;
dcmi->buffers_count = 0;
dcmi->active = NULL;
/*
* Start transfer if at least one buffer has been queued,
@ -650,15 +654,15 @@ static int dcmi_start_streaming(struct vb2_queue *vq, unsigned int count)
return 0;
}
dcmi->active = list_entry(dcmi->buffers.next, struct dcmi_buf, list);
list_del_init(&dcmi->active->list);
dev_dbg(dcmi->dev, "Start streaming, starting capture\n");
buf = list_entry(dcmi->buffers.next, struct dcmi_buf, list);
dcmi->active = buf;
dcmi->state = RUNNING;
dev_dbg(dcmi->dev, "Start streaming, starting capture\n");
spin_unlock_irq(&dcmi->irqlock);
ret = dcmi_start_capture(dcmi);
ret = dcmi_start_capture(dcmi, buf);
if (ret) {
dev_err(dcmi->dev, "%s: Start streaming failed, cannot start capture\n",
__func__);
@ -682,15 +686,11 @@ err_release_buffers:
* Return all buffers to vb2 in QUEUED state.
* This will give ownership back to userspace
*/
if (dcmi->active) {
buf = dcmi->active;
vb2_buffer_done(&buf->vb.vb2_buf, VB2_BUF_STATE_QUEUED);
dcmi->active = NULL;
}
list_for_each_entry_safe(buf, node, &dcmi->buffers, list) {
list_del_init(&buf->list);
vb2_buffer_done(&buf->vb.vb2_buf, VB2_BUF_STATE_QUEUED);
}
dcmi->active = NULL;
spin_unlock_irq(&dcmi->irqlock);
return ret;
@ -732,16 +732,13 @@ static void dcmi_stop_streaming(struct vb2_queue *vq)
}
/* Return all queued buffers to vb2 in ERROR state */
if (dcmi->active) {
buf = dcmi->active;
vb2_buffer_done(&buf->vb.vb2_buf, VB2_BUF_STATE_ERROR);
dcmi->active = NULL;
}
list_for_each_entry_safe(buf, node, &dcmi->buffers, list) {
list_del_init(&buf->list);
vb2_buffer_done(&buf->vb.vb2_buf, VB2_BUF_STATE_ERROR);
}
dcmi->active = NULL;
spin_unlock_irq(&dcmi->irqlock);
/* Stop all pending DMA operations */