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Commit d05051c8 authored by Mauro Carvalho Chehab's avatar Mauro Carvalho Chehab
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V4L/DVB (6997): Replace a very dirty hack on videobuf for a clean wait_event 



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: default avatarMauro Carvalho Chehab <mchehab@infradead.org>
parent c6243d9c

drivers/media/video/videobuf-core.c

+11 −4
Original line number Diff line number Diff line
@@ -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;

include/media/videobuf-core.h

+2 −0
Original line number Diff line number Diff line
@@ -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;