Patch "[media] vb2: Don't WARN when v4l2_buffer.bytesused is 0 for multiplanar buffers" has been added to the 4.1-stable tree

[<gregkh@linuxfoundation.org>]

This is a note to let you know that I've just added the patch titled

    [media] vb2: Don't WARN when v4l2_buffer.bytesused is 0 for multiplanar buffers

to the 4.1-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     vb2-don-t-warn-when-v4l2_buffer.bytesused-is-0-for-multiplanar-buffers.patch
and it can be found in the queue-4.1 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From 77a3c6fd90c94f635edb00d4a65f485687538791 Mon Sep 17 00:00:00 2001
From: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Date: Fri, 19 Jun 2015 08:50:07 -0300
Subject: [media] vb2: Don't WARN when v4l2_buffer.bytesused is 0 for multiplanar buffers

From: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>

commit 77a3c6fd90c94f635edb00d4a65f485687538791 upstream.

Commit f61bf13b6a07 ("[media] vb2: add allow_zero_bytesused flag to the
vb2_queue struct") added a WARN_ONCE to catch usage of a deprecated API
using a zero value for v4l2_buffer.bytesused.

However, the condition is checked incorrectly, as the v4L2_buffer
bytesused field is supposed to be ignored for multiplanar buffers. This
results in spurious warnings when using the multiplanar API.

Fix it by checking v4l2_buffer.bytesused for uniplanar buffers and
v4l2_plane.bytesused for multiplanar buffers.

Fixes: f61bf13b6a07 ("[media] vb2: add allow_zero_bytesused flag to the vb2_queue struct")

Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 drivers/media/v4l2-core/videobuf2-core.c |   33 +++++++++++++++++++++----------
 1 file changed, 23 insertions(+), 10 deletions(-)

--- a/drivers/media/v4l2-core/videobuf2-core.c
+++ b/drivers/media/v4l2-core/videobuf2-core.c
@@ -1237,6 +1237,23 @@ void vb2_discard_done(struct vb2_queue *
 }
 EXPORT_SYMBOL_GPL(vb2_discard_done);
 
+static void vb2_warn_zero_bytesused(struct vb2_buffer *vb)
+{
+	static bool __check_once __read_mostly;
+
+	if (__check_once)
+		return;
+
+	__check_once = true;
+	__WARN();
+
+	pr_warn_once("use of bytesused == 0 is deprecated and will be removed in the future,\n");
+	if (vb->vb2_queue->allow_zero_bytesused)
+		pr_warn_once("use VIDIOC_DECODER_CMD(V4L2_DEC_CMD_STOP) instead.\n");
+	else
+		pr_warn_once("use the actual size instead.\n");
+}
+
 /**
  * __fill_vb2_buffer() - fill a vb2_buffer with information provided in a
  * v4l2_buffer by the userspace. The caller has already verified that struct
@@ -1247,16 +1264,6 @@ static void __fill_vb2_buffer(struct vb2
 {
 	unsigned int plane;
 
-	if (V4L2_TYPE_IS_OUTPUT(b->type)) {
-		if (WARN_ON_ONCE(b->bytesused == 0)) {
-			pr_warn_once("use of bytesused == 0 is deprecated and will be removed in the future,\n");
-			if (vb->vb2_queue->allow_zero_bytesused)
-				pr_warn_once("use VIDIOC_DECODER_CMD(V4L2_DEC_CMD_STOP) instead.\n");
-			else
-				pr_warn_once("use the actual size instead.\n");
-		}
-	}
-
 	if (V4L2_TYPE_IS_MULTIPLANAR(b->type)) {
 		if (b->memory == V4L2_MEMORY_USERPTR) {
 			for (plane = 0; plane < vb->num_planes; ++plane) {
@@ -1297,6 +1304,9 @@ static void __fill_vb2_buffer(struct vb2
 				struct v4l2_plane *pdst = &v4l2_planes[plane];
 				struct v4l2_plane *psrc = &b->m.planes[plane];
 
+				if (psrc->bytesused == 0)
+					vb2_warn_zero_bytesused(vb);
+
 				if (vb->vb2_queue->allow_zero_bytesused)
 					pdst->bytesused = psrc->bytesused;
 				else
@@ -1331,6 +1341,9 @@ static void __fill_vb2_buffer(struct vb2
 		}
 
 		if (V4L2_TYPE_IS_OUTPUT(b->type)) {
+			if (b->bytesused == 0)
+				vb2_warn_zero_bytesused(vb);
+
 			if (vb->vb2_queue->allow_zero_bytesused)
 				v4l2_planes[0].bytesused = b->bytesused;
 			else


Patches currently in stable-queue which might be from laurent.pinchart+renesas@ideasonboard.com are

queue-4.1/vb2-don-t-warn-when-v4l2_buffer.bytesused-is-0-for-multiplanar-buffers.patch