diff options
author | Laurent Pinchart <laurent.pinchart@ideasonboard.com> | 2010-01-23 07:07:53 -0300 |
---|---|---|
committer | Mauro Carvalho Chehab <mchehab@redhat.com> | 2010-02-26 15:11:04 -0300 |
commit | e54532e591cd5b9ce77dbc8d9786ae9f600f101a (patch) | |
tree | 725c07637e0197acd3176827299d4186962221e4 /drivers/media/video/uvc/uvc_ctrl.c | |
parent | 59529081e092506edb81a42d914e2d0522f65ca7 (diff) |
V4L/DVB: uvcvideo: Clamp control values to the minimum and maximum values
When setting a control, the V4L2 specification requires drivers to
either clamp the control value to the [minimum, maximum] range or return
the -ERANGE error.
Fix the driver to clamp control values to the valid range in
uvc_ctrl_set() and make sure the value differs from the minimum by an
integer multiple of step.
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Tested-by: Márton Németh <nm127@freemail.hu>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Diffstat (limited to 'drivers/media/video/uvc/uvc_ctrl.c')
-rw-r--r-- | drivers/media/video/uvc/uvc_ctrl.c | 47 |
1 files changed, 43 insertions, 4 deletions
diff --git a/drivers/media/video/uvc/uvc_ctrl.c b/drivers/media/video/uvc/uvc_ctrl.c index 5ff50139084..f38bc6bbc3d 100644 --- a/drivers/media/video/uvc/uvc_ctrl.c +++ b/drivers/media/video/uvc/uvc_ctrl.c @@ -1021,19 +1021,57 @@ int uvc_ctrl_set(struct uvc_video_chain *chain, { struct uvc_control *ctrl; struct uvc_control_mapping *mapping; - s32 value = xctrl->value; + s32 value; + u32 step; + s32 min; + s32 max; int ret; ctrl = uvc_find_control(chain, xctrl->id, &mapping); if (ctrl == NULL || (ctrl->info->flags & UVC_CONTROL_SET_CUR) == 0) return -EINVAL; - if (mapping->v4l2_type == V4L2_CTRL_TYPE_MENU) { - if (value < 0 || value >= mapping->menu_count) + /* Clamp out of range values. */ + switch (mapping->v4l2_type) { + case V4L2_CTRL_TYPE_INTEGER: + if (!ctrl->cached) { + ret = uvc_ctrl_populate_cache(chain, ctrl); + if (ret < 0) + return ret; + } + + min = mapping->get(mapping, UVC_GET_MIN, + uvc_ctrl_data(ctrl, UVC_CTRL_DATA_MIN)); + max = mapping->get(mapping, UVC_GET_MAX, + uvc_ctrl_data(ctrl, UVC_CTRL_DATA_MAX)); + step = mapping->get(mapping, UVC_GET_RES, + uvc_ctrl_data(ctrl, UVC_CTRL_DATA_RES)); + + xctrl->value = min + (xctrl->value - min + step/2) / step * step; + xctrl->value = clamp(xctrl->value, min, max); + value = xctrl->value; + break; + + case V4L2_CTRL_TYPE_BOOLEAN: + xctrl->value = clamp(xctrl->value, 0, 1); + value = xctrl->value; + break; + + case V4L2_CTRL_TYPE_MENU: + if (xctrl->value < 0 || xctrl->value >= mapping->menu_count) return -ERANGE; - value = mapping->menu_info[value].value; + value = mapping->menu_info[xctrl->value].value; + break; + + default: + value = xctrl->value; + break; } + /* If the mapping doesn't span the whole UVC control, the current value + * needs to be loaded from the device to perform the read-modify-write + * operation. + */ if (!ctrl->loaded && (ctrl->info->size * 8) != mapping->size) { if ((ctrl->info->flags & UVC_CONTROL_GET_CUR) == 0) { memset(uvc_ctrl_data(ctrl, UVC_CTRL_DATA_CURRENT), @@ -1051,6 +1089,7 @@ int uvc_ctrl_set(struct uvc_video_chain *chain, ctrl->loaded = 1; } + /* Backup the current value in case we need to rollback later. */ if (!ctrl->dirty) { memcpy(uvc_ctrl_data(ctrl, UVC_CTRL_DATA_BACKUP), uvc_ctrl_data(ctrl, UVC_CTRL_DATA_CURRENT), |