Currently, this driver does not serialize its video4linux
ioctls, which is a bug, as race conditions might appear.
In addition, video_device and vb2_queue locks are now both
mandatory. Add them, and implement wait_prepare and
wait_finish.
To stay on the safe side, this commit uses a single mutex
for both locks. Better latency can be obtained by separating
these if needed.
Signed-off-by: Ezequiel Garcia <ezequiel@xxxxxxxxxxxxx>
---
It's not really related to this commit, but there is no
locking around vip->active in vip_irq() ?
Perhaps it's a non-issue, but it looks fishy.
vip_irq()
{
// ...
if (vip->active) { /* Acquisition is over on this buffer */
// ...
vb2_buffer_done(&vip->active->vb.vb2_buf, VB2_BUF_STATE_DONE);
}
}
---
drivers/media/pci/sta2x11/sta2x11_vip.c | 6 ++++++
1 file changed, 6 insertions(+)
diff --git a/drivers/media/pci/sta2x11/sta2x11_vip.c b/drivers/media/pci/sta2x11/sta2x11_vip.c
index dd199bfc1d45..d47b99c2100f 100644
--- a/drivers/media/pci/sta2x11/sta2x11_vip.c
+++ b/drivers/media/pci/sta2x11/sta2x11_vip.c
@@ -145,6 +145,7 @@ struct sta2x11_vip {
unsigned int sequence;
struct vip_buffer *active; /* current active buffer */
spinlock_t lock; /* Used in videobuf2 callback */
+ struct mutex v4l_lock;
/* Interrupt counters */
int tcount, bcount;
@@ -385,6 +386,8 @@ static const struct vb2_ops vip_video_qops = {
.buf_queue = buffer_queue,
.start_streaming = start_streaming,
.stop_streaming = stop_streaming,
+ .wait_prepare = vb2_ops_wait_prepare,
+ .wait_finish = vb2_ops_wait_finish,
};
@@ -870,6 +873,7 @@ static int sta2x11_vip_init_buffer(struct sta2x11_vip *vip)
vip->vb_vidq.mem_ops = &vb2_dma_contig_memops;
vip->vb_vidq.timestamp_flags = V4L2_BUF_FLAG_TIMESTAMP_MONOTONIC;
vip->vb_vidq.dev = &vip->pdev->dev;
+ vip->vb_vidq.lock = &vip->v4l_lock;
err = vb2_queue_init(&vip->vb_vidq);
if (err)
return err;
@@ -1035,6 +1039,7 @@ static int sta2x11_vip_init_one(struct pci_dev *pdev,
vip->std = V4L2_STD_PAL;
vip->format = formats_50[0];
vip->config = config;
+ mutex_init(&vip->v4l_lock);
ret = sta2x11_vip_init_controls(vip);
if (ret)
@@ -1081,6 +1086,7 @@ static int sta2x11_vip_init_one(struct pci_dev *pdev,
vip->video_dev = video_dev_template;
vip->video_dev.v4l2_dev = &vip->v4l2_dev;
vip->video_dev.queue = &vip->vb_vidq;
+ vip->video_dev.lock = &vip->v4l_lock;
video_set_drvdata(&vip->video_dev, vip);
ret = video_register_device(&vip->video_dev, VFL_TYPE_GRABBER, -1);
--
2.16.3
