videobuf: revert changeset #7490:5b77f099a151

From: Mauro Carvalho Chehab <mchehab@infradead.org>

This changeset were supposed to optimize mmap() support on vmalloc. However, it
just broke mmap() on real devices. Revert the changeset to make mmap() to work
again.

Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>

3 files changed, 40 insertions, 35 deletions

diff --git a/linux/drivers/media/video/videobuf-core.c b/linux/drivers/media/video/videobuf-core.c
index 7138410fa..52d9a766c 100644
--- a/linux/drivers/media/video/videobuf-core.c
+++ b/linux/drivers/media/video/videobuf-core.c
@@ -92,17 +92,25 @@ 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);
 }
 
 /* --------------------------------------------------------------------- */
 
-static int videobuf_mmap_setup_default(struct videobuf_queue *q,
-					struct videobuf_buffer *vb)
-{
-	return 0;
-}
-
 
 void videobuf_queue_core_init(struct videobuf_queue *q,
 			 struct videobuf_queue_ops *ops,
@@ -124,9 +132,6 @@ void videobuf_queue_core_init(struct videobuf_queue *q,
 	q->priv_data = priv;
 	q->int_ops   = int_ops;
 
-	if (!q->int_ops->mmap_setup)
-		q->int_ops->mmap_setup = videobuf_mmap_setup_default;
-
 	/* All buffer operations are mandatory */
 	BUG_ON(!q->ops->buf_setup);
 	BUG_ON(!q->ops->buf_prepare);
@@ -304,6 +309,8 @@ static int __videobuf_mmap_free(struct videobuf_queue *q)
 
 	rc  = CALL(q, mmap_free, q);
 
+	q->is_mmapped = 0;
+
 	if (rc < 0)
 		return rc;
 
@@ -355,9 +362,6 @@ static int __videobuf_mmap_setup(struct videobuf_queue *q,
 		switch (memory) {
 		case V4L2_MEMORY_MMAP:
 			q->bufs[i]->boff  = bsize * i;
-			err = q->int_ops->mmap_setup(q, q->bufs[i]);
-			if (err)
-				break;
 			break;
 		case V4L2_MEMORY_USERPTR:
 		case V4L2_MEMORY_OVERLAY:
@@ -1080,6 +1084,7 @@ int videobuf_mmap_mapper(struct videobuf_queue *q,
 
 	mutex_lock(&q->vb_lock);
 	retval = CALL(q, mmap_mapper, q, vma);
+	q->is_mmapped = 1;
 	mutex_unlock(&q->vb_lock);
 
 	return retval;
diff --git a/linux/drivers/media/video/videobuf-vmalloc.c b/linux/drivers/media/video/videobuf-vmalloc.c
index 9e6ff640e..6cdd27d55 100644
--- a/linux/drivers/media/video/videobuf-vmalloc.c
+++ b/linux/drivers/media/video/videobuf-vmalloc.c
@@ -152,26 +152,21 @@ static int __videobuf_iolock (struct videobuf_queue* q,
 				(unsigned long)mem->vmalloc,
 				pages << PAGE_SHIFT);
 
-	return 0;
-}
-
-static int __videobuf_mmap_setup(struct videobuf_queue *q,
-			      struct videobuf_buffer *vb)
-{
-	int retval = 0;
-	BUG_ON(vb->memory != V4L2_MEMORY_MMAP);
-	if (vb->state == VIDEOBUF_NEEDS_INIT) {
-		/* bsize == size since the buffer needs to be large enough to
-		 * hold an entire frame, not the case in the read case for
-		 * example*/
-		vb->size = vb->bsize;
-		retval = __videobuf_iolock(q, vb, NULL);
-		if (!retval) {
-			/* Don't IOLOCK later */
-			vb->state = VIDEOBUF_IDLE;
+	/* It seems that some kernel versions need to do remap *after*
+	   the mmap() call
+	 */
+	if (mem->vma) {
+		int retval=remap_vmalloc_range(mem->vma, mem->vmalloc,0);
+		kfree(mem->vma);
+		mem->vma=NULL;
+		if (retval<0) {
+			dprintk(1,"mmap app bug: remap_vmalloc_range area %p error %d\n",
+				mem->vmalloc,retval);
+			return retval;
 		}
 	}
-	return retval;
+
+	return 0;
 }
 
 static int __videobuf_sync(struct videobuf_queue *q,
@@ -244,8 +239,15 @@ static int __videobuf_mmap_mapper(struct videobuf_queue *q,
 	/* Try to remap memory */
 	retval=remap_vmalloc_range(vma, mem->vmalloc,0);
 	if (retval<0) {
-		dprintk(1, "mmap: failed to remap_vmalloc_range\n");
-		return -EINVAL;
+		dprintk(1,"mmap: postponing remap_vmalloc_range\n");
+
+		mem->vma=kmalloc(sizeof(*vma),GFP_KERNEL);
+		if (!mem->vma) {
+			kfree(map);
+			q->bufs[first]->map=NULL;
+			return -ENOMEM;
+		}
+		memcpy(mem->vma,vma,sizeof(*vma));
 	}
 
 	dprintk(1,"mmap %p: q=%p %08lx-%08lx (%lx) pgoff %08lx buf %d\n",
@@ -313,7 +315,6 @@ static struct videobuf_qtype_ops qops = {
 	.alloc        = __videobuf_alloc,
 	.iolock       = __videobuf_iolock,
 	.sync         = __videobuf_sync,
-	.mmap_setup   = __videobuf_mmap_setup,
 	.mmap_free    = __videobuf_mmap_free,
 	.mmap_mapper  = __videobuf_mmap_mapper,
 	.video_copy_to_user = __videobuf_copy_to_user,
diff --git a/linux/include/media/videobuf-core.h b/linux/include/media/videobuf-core.h
index 18b0ba615..ea269cec4 100644
--- a/linux/include/media/videobuf-core.h
+++ b/linux/include/media/videobuf-core.h
@@ -144,8 +144,6 @@ struct videobuf_qtype_ops {
 				 int vbihack,
 				 int nonblocking);
 	int (*mmap_free)	(struct videobuf_queue *q);
-	int (*mmap_setup)	(struct videobuf_queue *q,
-				 struct videobuf_buffer *vb);
 	int (*mmap_mapper)	(struct videobuf_queue *q,
 				struct vm_area_struct *vma);
 };
@@ -172,6 +170,7 @@ 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;