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>
---
drivers/staging/media/davinci_vpfe/vpfe_video.c | 6 +++++-
drivers/staging/media/davinci_vpfe/vpfe_video.h | 2 +-
2 files changed, 6 insertions(+), 2 deletions(-)
diff --git a/drivers/staging/media/davinci_vpfe/vpfe_video.c b/drivers/staging/media/davinci_vpfe/vpfe_video.c
index 390fc98d07dd..1269a983455e 100644
--- a/drivers/staging/media/davinci_vpfe/vpfe_video.c
+++ b/drivers/staging/media/davinci_vpfe/vpfe_video.c
@@ -1312,6 +1312,8 @@ static const struct vb2_ops video_qops = {
.stop_streaming = vpfe_stop_streaming,
.buf_cleanup = vpfe_buf_cleanup,
.buf_queue = vpfe_buffer_queue,
+ .wait_prepare = vb2_ops_wait_prepare,
+ .wait_finish = vb2_ops_wait_finish,
};
/*
@@ -1357,6 +1359,7 @@ static int vpfe_reqbufs(struct file *file, void *priv,
q->buf_struct_size = sizeof(struct vpfe_cap_buffer);
q->timestamp_flags = V4L2_BUF_FLAG_TIMESTAMP_MONOTONIC;
q->dev = vpfe_dev->pdev;
+ q->lock = &video->lock;
ret = vb2_queue_init(q);
if (ret) {
@@ -1598,17 +1601,18 @@ int vpfe_video_init(struct vpfe_video_device *video, const char *name)
return -EINVAL;
}
/* Initialize field of video device */
+ mutex_init(&video->lock);
video->video_dev.release = video_device_release;
video->video_dev.fops = &vpfe_fops;
video->video_dev.ioctl_ops = &vpfe_ioctl_ops;
video->video_dev.minor = -1;
video->video_dev.tvnorms = 0;
+ video->video_dev.lock = &video->lock;
snprintf(video->video_dev.name, sizeof(video->video_dev.name),
"DAVINCI VIDEO %s %s", name, direction);
spin_lock_init(&video->irqlock);
spin_lock_init(&video->dma_queue_lock);
- mutex_init(&video->lock);
ret = media_entity_pads_init(&video->video_dev.entity,
1, &video->pad);
if (ret < 0)
diff --git a/drivers/staging/media/davinci_vpfe/vpfe_video.h b/drivers/staging/media/davinci_vpfe/vpfe_video.h
index 22136d3dadcb..4bbd219e8329 100644
--- a/drivers/staging/media/davinci_vpfe/vpfe_video.h
+++ b/drivers/staging/media/davinci_vpfe/vpfe_video.h
@@ -128,7 +128,7 @@ struct vpfe_video_device {
spinlock_t irqlock;
/* IRQ lock for DMA queue */
spinlock_t dma_queue_lock;
- /* lock used to access this structure */
+ /* lock used to serialize all video4linux ioctls */
struct mutex lock;
/* number of users performing IO */
u32 io_usrs;
--
2.16.3
