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authorLaurent Pinchart <laurent.pinchart@ideasonboard.com>2010-01-23 07:07:53 -0300
committerMauro Carvalho Chehab <mchehab@redhat.com>2010-02-26 15:11:04 -0300
commite54532e591cd5b9ce77dbc8d9786ae9f600f101a (patch)
tree725c07637e0197acd3176827299d4186962221e4 /drivers/media/video/uvc
parent59529081e092506edb81a42d914e2d0522f65ca7 (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')
-rw-r--r--drivers/media/video/uvc/uvc_ctrl.c47
-rw-r--r--drivers/media/video/uvc/uvc_v4l2.c2
2 files changed, 45 insertions, 4 deletions
diff --git a/drivers/media/video/uvc/uvc_ctrl.c b/drivers/media/video/uvc/uvc_ctrl.c
index 5ff501390842..f38bc6bbc3d2 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),
diff --git a/drivers/media/video/uvc/uvc_v4l2.c b/drivers/media/video/uvc/uvc_v4l2.c
index 23239a4adefe..bf1fc7f29ca7 100644
--- a/drivers/media/video/uvc/uvc_v4l2.c
+++ b/drivers/media/video/uvc/uvc_v4l2.c
@@ -549,6 +549,8 @@ static long uvc_v4l2_do_ioctl(struct file *file, unsigned int cmd, void *arg)
return ret;
}
ret = uvc_ctrl_commit(chain);
+ if (ret == 0)
+ ctrl->value = xctrl.value;
break;
}