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path: root/drivers/media/video/videobuf-core.c
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Diffstat (limited to 'drivers/media/video/videobuf-core.c')
-rw-r--r--drivers/media/video/videobuf-core.c212
1 files changed, 124 insertions, 88 deletions
diff --git a/drivers/media/video/videobuf-core.c b/drivers/media/video/videobuf-core.c
index eab79ffdf56..982f4463896 100644
--- a/drivers/media/video/videobuf-core.c
+++ b/drivers/media/video/videobuf-core.c
@@ -64,32 +64,25 @@ void *videobuf_alloc(struct videobuf_queue *q)
return vb;
}
+#define WAITON_CONDITION (vb->state != VIDEOBUF_ACTIVE &&\
+ vb->state != VIDEOBUF_QUEUED)
int videobuf_waiton(struct videobuf_buffer *vb, int non_blocking, int intr)
{
- int retval = 0;
- DECLARE_WAITQUEUE(wait, current);
-
MAGIC_CHECK(vb->magic, MAGIC_BUFFER);
- add_wait_queue(&vb->done, &wait);
- while (vb->state == VIDEOBUF_ACTIVE || vb->state == VIDEOBUF_QUEUED) {
- if (non_blocking) {
- retval = -EAGAIN;
- break;
- }
- set_current_state(intr ? TASK_INTERRUPTIBLE
- : TASK_UNINTERRUPTIBLE);
- if (vb->state == VIDEOBUF_ACTIVE ||
- vb->state == VIDEOBUF_QUEUED)
- schedule();
- set_current_state(TASK_RUNNING);
- if (intr && signal_pending(current)) {
- dprintk(1, "buffer waiton: -EINTR\n");
- retval = -EINTR;
- break;
- }
+
+ if (non_blocking) {
+ if (WAITON_CONDITION)
+ return 0;
+ else
+ return -EAGAIN;
}
- remove_wait_queue(&vb->done, &wait);
- return retval;
+
+ if (intr)
+ return wait_event_interruptible(vb->done, WAITON_CONDITION);
+ else
+ wait_event(vb->done, WAITON_CONDITION);
+
+ return 0;
}
int videobuf_iolock(struct videobuf_queue *q, struct videobuf_buffer *vb,
@@ -98,29 +91,25 @@ int videobuf_iolock(struct videobuf_queue *q, struct videobuf_buffer *vb,
MAGIC_CHECK(vb->magic, MAGIC_BUFFER);
MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
- /* This is required to avoid OOPS on some cases,
- since mmap_mapper() method should be called before _iolock.
- On some cases, the mmap_mapper() is called only after scheduling.
- */
- if (vb->memory == V4L2_MEMORY_MMAP) {
- wait_event_timeout(vb->done, q->is_mmapped,
- msecs_to_jiffies(100));
- if (!q->is_mmapped) {
- printk(KERN_ERR
- "Error: mmap_mapper() never called!\n");
- return -EINVAL;
- }
- }
-
return CALL(q, iolock, q, vb, fbuf);
}
+void *videobuf_queue_to_vmalloc (struct videobuf_queue *q,
+ struct videobuf_buffer *buf)
+{
+ if (q->int_ops->vmalloc)
+ return q->int_ops->vmalloc(buf);
+ else
+ return NULL;
+}
+EXPORT_SYMBOL_GPL(videobuf_queue_to_vmalloc);
+
/* --------------------------------------------------------------------- */
void videobuf_queue_core_init(struct videobuf_queue *q,
struct videobuf_queue_ops *ops,
- void *dev,
+ struct device *dev,
spinlock_t *irqlock,
enum v4l2_buf_type type,
enum v4l2_field field,
@@ -144,10 +133,14 @@ void videobuf_queue_core_init(struct videobuf_queue *q,
BUG_ON(!q->ops->buf_queue);
BUG_ON(!q->ops->buf_release);
+ /* Lock is mandatory for queue_cancel to work */
+ BUG_ON(!irqlock);
+
/* Having implementations for abstract methods are mandatory */
BUG_ON(!q->int_ops);
mutex_init(&q->vb_lock);
+ init_waitqueue_head(&q->wait);
INIT_LIST_HEAD(&q->stream);
}
@@ -195,19 +188,22 @@ void videobuf_queue_cancel(struct videobuf_queue *q)
unsigned long flags = 0;
int i;
+ q->streaming = 0;
+ q->reading = 0;
+ wake_up_interruptible_sync(&q->wait);
+
/* remove queued buffers from list */
- if (q->irqlock)
- spin_lock_irqsave(q->irqlock, flags);
+ spin_lock_irqsave(q->irqlock, flags);
for (i = 0; i < VIDEO_MAX_FRAME; i++) {
if (NULL == q->bufs[i])
continue;
if (q->bufs[i]->state == VIDEOBUF_QUEUED) {
list_del(&q->bufs[i]->queue);
q->bufs[i]->state = VIDEOBUF_ERROR;
+ wake_up_all(&q->bufs[i]->done);
}
}
- if (q->irqlock)
- spin_unlock_irqrestore(q->irqlock, flags);
+ spin_unlock_irqrestore(q->irqlock, flags);
/* free all buffers + clear queue */
for (i = 0; i < VIDEO_MAX_FRAME; i++) {
@@ -563,14 +559,13 @@ int videobuf_qbuf(struct videobuf_queue *q,
list_add_tail(&buf->stream, &q->stream);
if (q->streaming) {
- if (q->irqlock)
- spin_lock_irqsave(q->irqlock, flags);
+ spin_lock_irqsave(q->irqlock, flags);
q->ops->buf_queue(q, buf);
- if (q->irqlock)
- spin_unlock_irqrestore(q->irqlock, flags);
+ spin_unlock_irqrestore(q->irqlock, flags);
}
dprintk(1, "qbuf: succeded\n");
retval = 0;
+ wake_up_interruptible_sync(&q->wait);
done:
mutex_unlock(&q->vb_lock);
@@ -581,35 +576,88 @@ int videobuf_qbuf(struct videobuf_queue *q,
return retval;
}
-int videobuf_dqbuf(struct videobuf_queue *q,
- struct v4l2_buffer *b, int nonblocking)
+
+/* Locking: Caller holds q->vb_lock */
+static int stream_next_buffer_check_queue(struct videobuf_queue *q, int noblock)
{
- struct videobuf_buffer *buf;
int retval;
- MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
-
- mutex_lock(&q->vb_lock);
- retval = -EBUSY;
- if (q->reading) {
- dprintk(1, "dqbuf: Reading running...\n");
- goto done;
- }
- retval = -EINVAL;
- if (b->type != q->type) {
- dprintk(1, "dqbuf: Wrong type.\n");
+checks:
+ if (!q->streaming) {
+ dprintk(1, "next_buffer: Not streaming\n");
+ retval = -EINVAL;
goto done;
}
+
if (list_empty(&q->stream)) {
- dprintk(1, "dqbuf: stream running\n");
- goto done;
+ if (noblock) {
+ retval = -EAGAIN;
+ dprintk(2, "next_buffer: no buffers to dequeue\n");
+ goto done;
+ } else {
+ dprintk(2, "next_buffer: waiting on buffer\n");
+
+ /* Drop lock to avoid deadlock with qbuf */
+ mutex_unlock(&q->vb_lock);
+
+ /* Checking list_empty and streaming is safe without
+ * locks because we goto checks to validate while
+ * holding locks before proceeding */
+ retval = wait_event_interruptible(q->wait,
+ !list_empty(&q->stream) || !q->streaming);
+ mutex_lock(&q->vb_lock);
+
+ if (retval)
+ goto done;
+
+ goto checks;
+ }
}
+
+ retval = 0;
+
+done:
+ return retval;
+}
+
+
+/* Locking: Caller holds q->vb_lock */
+static int stream_next_buffer(struct videobuf_queue *q,
+ struct videobuf_buffer **vb, int nonblocking)
+{
+ int retval;
+ struct videobuf_buffer *buf = NULL;
+
+ retval = stream_next_buffer_check_queue(q, nonblocking);
+ if (retval)
+ goto done;
+
buf = list_entry(q->stream.next, struct videobuf_buffer, stream);
retval = videobuf_waiton(buf, nonblocking, 1);
+ if (retval < 0)
+ goto done;
+
+ *vb = buf;
+done:
+ return retval;
+}
+
+int videobuf_dqbuf(struct videobuf_queue *q,
+ struct v4l2_buffer *b, int nonblocking)
+{
+ struct videobuf_buffer *buf = NULL;
+ int retval;
+
+ MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
+
+ mutex_lock(&q->vb_lock);
+
+ retval = stream_next_buffer(q, &buf, nonblocking);
if (retval < 0) {
- dprintk(1, "dqbuf: waiton returned %d\n", retval);
+ dprintk(1, "dqbuf: next_buffer error: %i\n", retval);
goto done;
}
+
switch (buf->state) {
case VIDEOBUF_ERROR:
dprintk(1, "dqbuf: state is error\n");
@@ -650,14 +698,13 @@ int videobuf_streamon(struct videobuf_queue *q)
if (q->streaming)
goto done;
q->streaming = 1;
- if (q->irqlock)
- spin_lock_irqsave(q->irqlock, flags);
+ spin_lock_irqsave(q->irqlock, flags);
list_for_each_entry(buf, &q->stream, stream)
if (buf->state == VIDEOBUF_PREPARED)
q->ops->buf_queue(q, buf);
- if (q->irqlock)
- spin_unlock_irqrestore(q->irqlock, flags);
+ spin_unlock_irqrestore(q->irqlock, flags);
+ wake_up_interruptible_sync(&q->wait);
done:
mutex_unlock(&q->vb_lock);
return retval;
@@ -670,7 +717,6 @@ static int __videobuf_streamoff(struct videobuf_queue *q)
return -EINVAL;
videobuf_queue_cancel(q);
- q->streaming = 0;
return 0;
}
@@ -712,11 +758,9 @@ static ssize_t videobuf_read_zerocopy(struct videobuf_queue *q,
goto done;
/* start capture & wait */
- if (q->irqlock)
- spin_lock_irqsave(q->irqlock, flags);
+ spin_lock_irqsave(q->irqlock, flags);
q->ops->buf_queue(q, q->read_buf);
- if (q->irqlock)
- spin_unlock_irqrestore(q->irqlock, flags);
+ spin_unlock_irqrestore(q->irqlock, flags);
retval = videobuf_waiton(q->read_buf, 0, 0);
if (0 == retval) {
CALL(q, sync, q, q->read_buf);
@@ -740,14 +784,13 @@ ssize_t videobuf_read_one(struct videobuf_queue *q,
{
enum v4l2_field field;
unsigned long flags = 0;
- unsigned size, nbufs;
+ unsigned size = 0, nbufs = 1;
int retval;
MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
mutex_lock(&q->vb_lock);
- nbufs = 1; size = 0;
q->ops->buf_setup(q, &nbufs, &size);
if (NULL == q->read_buf &&
@@ -778,12 +821,11 @@ ssize_t videobuf_read_one(struct videobuf_queue *q,
q->read_buf = NULL;
goto done;
}
- if (q->irqlock)
- spin_lock_irqsave(q->irqlock, flags);
+ spin_lock_irqsave(q->irqlock, flags);
q->ops->buf_queue(q, q->read_buf);
- if (q->irqlock)
- spin_unlock_irqrestore(q->irqlock, flags);
+ spin_unlock_irqrestore(q->irqlock, flags);
+
q->read_off = 0;
}
@@ -849,12 +891,10 @@ static int __videobuf_read_start(struct videobuf_queue *q)
return err;
list_add_tail(&q->bufs[i]->stream, &q->stream);
}
- if (q->irqlock)
- spin_lock_irqsave(q->irqlock, flags);
+ spin_lock_irqsave(q->irqlock, flags);
for (i = 0; i < count; i++)
q->ops->buf_queue(q, q->bufs[i]);
- if (q->irqlock)
- spin_unlock_irqrestore(q->irqlock, flags);
+ spin_unlock_irqrestore(q->irqlock, flags);
q->reading = 1;
return 0;
}
@@ -863,7 +903,6 @@ static void __videobuf_read_stop(struct videobuf_queue *q)
{
int i;
-
videobuf_queue_cancel(q);
__videobuf_mmap_free(q);
INIT_LIST_HEAD(&q->stream);
@@ -874,7 +913,6 @@ static void __videobuf_read_stop(struct videobuf_queue *q)
q->bufs[i] = NULL;
}
q->read_buf = NULL;
- q->reading = 0;
}
@@ -919,7 +957,7 @@ ssize_t videobuf_read_stream(struct videobuf_queue *q,
MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
- dprintk(2, "%s\n", __FUNCTION__);
+ dprintk(2, "%s\n", __func__);
mutex_lock(&q->vb_lock);
retval = -EBUSY;
if (q->streaming)
@@ -968,11 +1006,9 @@ ssize_t videobuf_read_stream(struct videobuf_queue *q,
if (q->read_off == q->read_buf->size) {
list_add_tail(&q->read_buf->stream,
&q->stream);
- if (q->irqlock)
- spin_lock_irqsave(q->irqlock, flags);
+ spin_lock_irqsave(q->irqlock, flags);
q->ops->buf_queue(q, q->read_buf);
- if (q->irqlock)
- spin_unlock_irqrestore(q->irqlock, flags);
+ spin_unlock_irqrestore(q->irqlock, flags);
q->read_buf = NULL;
}
if (retval < 0)