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authorMauro Carvalho Chehab <mchehab@redhat.com>2011-02-22 01:00:58 -0300
committerMauro Carvalho Chehab <mchehab@redhat.com>2011-03-21 20:32:04 -0300
commitfb8decfabdf841a199b297076ff9f890dee55e53 (patch)
tree5d6c57486d1af3197db38a6bc9d203b49c654441 /drivers/media/video/em28xx
parent78e51566f0c56daa58f7bbe2591336b7d478c148 (diff)
[media] em28xx: properly handle subdev controls
Subdev controls return codes are evil, as they return -EINVAL to mean both unsupported and invalid arguments. Due to that, we need to use a trick to identify what controls are supported by a subdev. Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Diffstat (limited to 'drivers/media/video/em28xx')
-rw-r--r--drivers/media/video/em28xx/em28xx-video.c31
1 files changed, 28 insertions, 3 deletions
diff --git a/drivers/media/video/em28xx/em28xx-video.c b/drivers/media/video/em28xx/em28xx-video.c
index 1ddd3ee22812..a83131bd00b2 100644
--- a/drivers/media/video/em28xx/em28xx-video.c
+++ b/drivers/media/video/em28xx/em28xx-video.c
@@ -1387,6 +1387,27 @@ static int vidioc_queryctrl(struct file *file, void *priv,
return -EINVAL;
}
+/*
+ * FIXME: This is an indirect way to check if a control exists at a
+ * subdev. Instead of that hack, maybe the better would be to change all
+ * subdevs to return -ENOIOCTLCMD, if an ioctl is not supported.
+ */
+static int check_subdev_ctrl(struct em28xx *dev, int id)
+{
+ struct v4l2_queryctrl qc;
+
+ memset(&qc, 0, sizeof(qc));
+ qc.id = id;
+
+ /* enumerate V4L2 device controls */
+ v4l2_device_call_all(&dev->v4l2_dev, 0, core, queryctrl, &qc);
+
+ if (qc.type)
+ return 0;
+ else
+ return -EINVAL;
+}
+
static int vidioc_g_ctrl(struct file *file, void *priv,
struct v4l2_control *ctrl)
{
@@ -1399,7 +1420,6 @@ static int vidioc_g_ctrl(struct file *file, void *priv,
return rc;
rc = 0;
-
/* Set an AC97 control */
if (dev->audio_mode.ac97 != EM28XX_NO_AC97)
rc = ac97_get_ctrl(dev, ctrl);
@@ -1408,6 +1428,9 @@ static int vidioc_g_ctrl(struct file *file, void *priv,
/* It were not an AC97 control. Sends it to the v4l2 dev interface */
if (rc == 1) {
+ if (check_subdev_ctrl(dev, ctrl->id))
+ return -EINVAL;
+
v4l2_device_call_all(&dev->v4l2_dev, 0, core, g_ctrl, ctrl);
rc = 0;
}
@@ -1434,8 +1457,10 @@ static int vidioc_s_ctrl(struct file *file, void *priv,
/* It isn't an AC97 control. Sends it to the v4l2 dev interface */
if (rc == 1) {
- rc = v4l2_device_call_until_err(&dev->v4l2_dev, 0, core, s_ctrl, ctrl);
-
+ rc = check_subdev_ctrl(dev, ctrl->id);
+ if (!rc)
+ v4l2_device_call_all(&dev->v4l2_dev, 0,
+ core, s_ctrl, ctrl);
/*
* In the case of non-AC97 volume controls, we still need
* to do some setups at em28xx, in order to mute/unmute