The VIDIOC_S_FMT is a write-read ioctl: it sets the format and returns
the current format in case of success. The parameter of VIDIOC_S_FMT
ioctl is a pointer to struct v4l2_format. [1] This structure contains some
fields which are not used depending on the .type value. These unused
fields are filled with zeros with this patch.
The patch was tested with v4l-test 0.12 [2] with vivi and with
gspca_sunplus driver together with Trust 610 LCD pow...@m ZOOM.
References:
[1] V4L2 API specification, revision 0.24
http://v4l2spec.bytesex.org/spec/r10944.htm
[2] v4l-test: Test environment for Video For Linux Two API
http://v4l-test.sourceforge.net/
Signed-off-by: Márton Németh <nm...@freemail.hu>
---
--- linux-2.6.30-rc3/drivers/media/video/v4l2-ioctl.c.orig 2009-04-22
05:07:00.000000000 +0200
+++ linux-2.6.30-rc3/drivers/media/video/v4l2-ioctl.c 2009-04-25
09:05:42.000000000 +0200
@@ -777,44 +777,61 @@
{
struct v4l2_format *f = (struct v4l2_format *)arg;
+#define CLEAR_UNUSED_FIELDS(data, last_member) \
+ memset(((u8 *)f)+ \
+ offsetof(struct v4l2_format, fmt)+ \
+ sizeof(struct v4l2_ ## last_member), \
+ 0, \
+ sizeof(*f)- \
+ offsetof(struct v4l2_format, fmt)+ \
+ sizeof(struct v4l2_ ## last_member))
+
/* FIXME: Should be one dump per type */
dbgarg(cmd, "type=%s\n", prt_names(f->type, v4l2_type_names));
switch (f->type) {
case V4L2_BUF_TYPE_VIDEO_CAPTURE:
+ CLEAR_UNUSED_FIELDS(f, pix_format);
v4l_print_pix_fmt(vfd, &f->fmt.pix);
if (ops->vidioc_s_fmt_vid_cap)
ret = ops->vidioc_s_fmt_vid_cap(file, fh, f);
break;
case V4L2_BUF_TYPE_VIDEO_OVERLAY:
+ CLEAR_UNUSED_FIELDS(f, window);
if (ops->vidioc_s_fmt_vid_overlay)
ret = ops->vidioc_s_fmt_vid_overlay(file,
fh, f);
break;
case V4L2_BUF_TYPE_VIDEO_OUTPUT:
+ CLEAR_UNUSED_FIELDS(f, pix_format);
v4l_print_pix_fmt(vfd, &f->fmt.pix);
if (ops->vidioc_s_fmt_vid_out)
ret = ops->vidioc_s_fmt_vid_out(file, fh, f);
break;
case V4L2_BUF_TYPE_VIDEO_OUTPUT_OVERLAY:
+ CLEAR_UNUSED_FIELDS(f, window);
if (ops->vidioc_s_fmt_vid_out_overlay)
ret = ops->vidioc_s_fmt_vid_out_overlay(file,
fh, f);
break;
case V4L2_BUF_TYPE_VBI_CAPTURE:
+ CLEAR_UNUSED_FIELDS(f, vbi_format);
if (ops->vidioc_s_fmt_vbi_cap)
ret = ops->vidioc_s_fmt_vbi_cap(file, fh, f);
break;
case V4L2_BUF_TYPE_VBI_OUTPUT:
+ CLEAR_UNUSED_FIELDS(f, vbi_format);
if (ops->vidioc_s_fmt_vbi_out)
ret = ops->vidioc_s_fmt_vbi_out(file, fh, f);
break;
case V4L2_BUF_TYPE_SLICED_VBI_CAPTURE:
+ CLEAR_UNUSED_FIELDS(f, sliced_vbi_format);
if (ops->vidioc_s_fmt_sliced_vbi_cap)
ret = ops->vidioc_s_fmt_sliced_vbi_cap(file,
fh, f);
break;
case V4L2_BUF_TYPE_SLICED_VBI_OUTPUT:
+ CLEAR_UNUSED_FIELDS(f, sliced_vbi_format);
if (ops->vidioc_s_fmt_sliced_vbi_out)
ret = ops->vidioc_s_fmt_sliced_vbi_out(file,
fh, f);
--
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