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V4L/DVB (6997): Replace a very dirty hack on videobuf for a clean wait_event

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In order to videobuf_iolock to work, mmap_mapper should be called first.
Otherwise, an OOPS is generated.

On some cases, .mmap file handler used to took some time to be called. On those
situations, mmap_mmapper() were called after iolock.

This patch properly waits for mmap_mapper to be called, otherwise generating an
error.

Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>
This commit is contained in:
Mauro Carvalho Chehab 2008-01-10 07:33:03 -03:00
parent c6243d9c3d
commit d05051c82e
2 changed files with 13 additions and 4 deletions
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15
drivers/media/video/videobuf-core.c
View File

@ -98,13 +98,15 @@ 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);
/* FIXME: This is required to avoid OOPS on some cases,
/* 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.
However, this way is just too dirty! Better to wait for some event.
*/
schedule_timeout(HZ);
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);
}
@ -300,7 +302,11 @@ static int __videobuf_mmap_free(struct videobuf_queue *q)
MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
rc = CALL(q, mmap_free, q);
q->is_mmapped = 0;
if (rc < 0)
return rc;
@ -1022,6 +1028,7 @@ int videobuf_mmap_mapper(struct videobuf_queue *q,
mutex_lock(&q->lock);
retval = CALL(q, mmap_mapper, q, vma);
q->is_mmapped = 1;
mutex_unlock(&q->lock);
return retval;

2
include/media/videobuf-core.h
View File

@ -164,6 +164,8 @@ struct videobuf_queue {
unsigned int streaming:1;
unsigned int reading:1;
unsigned int is_mmapped:1;
/* capture via mmap() + ioctl(QBUF/DQBUF) */
struct list_head stream;