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: Mauro Carvalho Chehab <mchehab@infradead.org>
diff --git a/drivers/media/video/videobuf-core.c b/drivers/media/video/videobuf-core.c
index 43fe3f7..c3adbd6 100644
--- a/drivers/media/video/videobuf-core.c
+++ b/drivers/media/video/videobuf-core.c
@@ -98,13 +98,15 @@
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 @@
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 @@
mutex_lock(&q->lock);
retval = CALL(q, mmap_mapper, q, vma);
+ q->is_mmapped = 1;
mutex_unlock(&q->lock);
return retval;
diff --git a/include/media/videobuf-core.h b/include/media/videobuf-core.h
index 7aa7a7b..97f14d4 100644
--- a/include/media/videobuf-core.h
+++ b/include/media/videobuf-core.h
@@ -164,6 +164,8 @@
unsigned int streaming:1;
unsigned int reading:1;
+ unsigned int is_mmapped:1;
+
/* capture via mmap() + ioctl(QBUF/DQBUF) */
struct list_head stream;