[PATCH] vb2: fix multiplanar read() with non-zero data_offset

[PATCH] vb2: fix multiplanar read() with non-zero data_offset

[Hans Verkuil]

If this is a multiplanar buf_type and the plane we want to read has a
non-zero data_offset, then that data_offset was not taken into account.

Note that read() or write() for formats with more than one plane is currently
not allowed, hence the use of 'planes[0]' since this is only relevant for a
single-plane format.

diff --git a/drivers/media/v4l2-core/videobuf2-core.c b/drivers/media/v4l2-core/videobuf2-core.c
index c359006..0e3d927 100644
--- a/drivers/media/v4l2-core/videobuf2-core.c
+++ b/drivers/media/v4l2-core/videobuf2-core.c
@@ -2959,6 +2959,12 @@ static size_t __vb2_perform_fileio(struct vb2_queue *q, char __user *data, size_
 		buf->queued = 0;
 		buf->size = read ? vb2_get_plane_payload(q->bufs[index], 0)
 				 : vb2_plane_size(q->bufs[index], 0);
+		/* Compensate for data_offset on read in the multiplanar case. */
+		if (is_multiplanar && read &&
+		    fileio->b.m.planes[0].data_offset < buf->size) {
+			buf->pos = fileio->b.m.planes[0].data_offset;
+			buf->size -= buf->pos;
+		}
 	} else {
 		buf = &fileio->bufs[index];
 	}

Re: [PATCH] vb2: fix multiplanar read() with non-zero data_offset

[Hans Verkuil]

On 07/25/14 11:09, Hans Verkuil wrote:
> If this is a multiplanar buf_type and the plane we want to read has a
> non-zero data_offset, then that data_offset was not taken into account.
> 
> Note that read() or write() for formats with more than one plane is currently
> not allowed, hence the use of 'planes[0]' since this is only relevant for a
> single-plane format.

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>

Forgot, sorry.

> 
> diff --git a/drivers/media/v4l2-core/videobuf2-core.c b/drivers/media/v4l2-core/videobuf2-core.c
> index c359006..0e3d927 100644
> --- a/drivers/media/v4l2-core/videobuf2-core.c
> +++ b/drivers/media/v4l2-core/videobuf2-core.c
> @@ -2959,6 +2959,12 @@ static size_t __vb2_perform_fileio(struct vb2_queue *q, char __user *data, size_
>  		buf->queued = 0;
>  		buf->size = read ? vb2_get_plane_payload(q->bufs[index], 0)
>  				 : vb2_plane_size(q->bufs[index], 0);
> +		/* Compensate for data_offset on read in the multiplanar case. */
> +		if (is_multiplanar && read &&
> +		    fileio->b.m.planes[0].data_offset < buf->size) {
> +			buf->pos = fileio->b.m.planes[0].data_offset;
> +			buf->size -= buf->pos;
> +		}
>  	} else {
>  		buf = &fileio->bufs[index];
>  	}
> --
> To unsubscribe from this list: send the line "unsubscribe linux-media" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html
>