diff options
| author | Mauro Carvalho Chehab <mchehab@redhat.com> | 2011-02-22 05:00:58 +0100 |
|---|---|---|
| committer | Mauro Carvalho Chehab <mchehab@redhat.com> | 2011-03-22 00:32:04 +0100 |
| commit | fb8decfabdf841a199b297076ff9f890dee55e53 (patch) | |
| tree | 5d6c57486d1af3197db38a6bc9d203b49c654441 | |
| parent | [media] em28xx: Fix return value for s_ctrl (diff) | |
| download | linux-fb8decfabdf841a199b297076ff9f890dee55e53.tar.xz linux-fb8decfabdf841a199b297076ff9f890dee55e53.zip | |
[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>
| -rw-r--r-- | drivers/media/video/em28xx/em28xx-video.c | 31 |
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 |