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

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>
Cc: stable@vger.kernel.org # for v4.0
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>

diff --git a/drivers/media/v4l2-core/videobuf2-core.c b/drivers/media/v4l2-core/videobuf2-core.c
index d835814a24d48311539a48a98f7aba07b54412a8..93b315459098932381d61d282cdb3f04194b18ae 100644 (file)
--- a/drivers/media/v4l2-core/videobuf2-core.c
+++ b/drivers/media/v4l2-core/videobuf2-core.c
@@ -1242,6 +1242,23 @@ void vb2_discard_done(struct vb2_queue *q)
 }
 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
@@ -1252,16 +1269,6 @@ static void __fill_vb2_buffer(struct vb2_buffer *vb, const struct v4l2_buffer *b
 {
        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) {
@@ -1302,6 +1309,9 @@ static void __fill_vb2_buffer(struct vb2_buffer *vb, const struct v4l2_buffer *b
                                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
@@ -1336,6 +1346,9 @@ static void __fill_vb2_buffer(struct vb2_buffer *vb, const struct v4l2_buffer *b
                }
 
                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