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[media] uvcvideo: Lock controls mutex when querying menus

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uvc_find_control() must be called with the controls mutex locked. Fix
uvc_query_v4l2_menu() accordingly.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
This commit is contained in:
Laurent Pinchart 2010-11-21 07:58:54 -03:00 committed by Mauro Carvalho Chehab
parent ca9afe6f87
commit 23d9f3ef23
3 changed files with 50 additions and 38 deletions
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48
drivers/media/video/uvc/uvc_ctrl.c
View File

@ -785,7 +785,7 @@ static void __uvc_find_control(struct uvc_entity *entity, __u32 v4l2_id,
}
}
struct uvc_control *uvc_find_control(struct uvc_video_chain *chain,
static struct uvc_control *uvc_find_control(struct uvc_video_chain *chain,
__u32 v4l2_id, struct uvc_control_mapping **mapping)
{
struct uvc_control *ctrl = NULL;
@ -944,6 +944,52 @@ done:
return ret;
}
/*
* Mapping V4L2 controls to UVC controls can be straighforward if done well.
* Most of the UVC controls exist in V4L2, and can be mapped directly. Some
* must be grouped (for instance the Red Balance, Blue Balance and Do White
* Balance V4L2 controls use the White Balance Component UVC control) or
* otherwise translated. The approach we take here is to use a translation
* table for the controls that can be mapped directly, and handle the others
* manually.
*/
int uvc_query_v4l2_menu(struct uvc_video_chain *chain,
struct v4l2_querymenu *query_menu)
{
struct uvc_menu_info *menu_info;
struct uvc_control_mapping *mapping;
struct uvc_control *ctrl;
u32 index = query_menu->index;
u32 id = query_menu->id;
int ret;
memset(query_menu, 0, sizeof(*query_menu));
query_menu->id = id;
query_menu->index = index;
ret = mutex_lock_interruptible(&chain->ctrl_mutex);
if (ret < 0)
return -ERESTARTSYS;
ctrl = uvc_find_control(chain, query_menu->id, &mapping);
if (ctrl == NULL || mapping->v4l2_type != V4L2_CTRL_TYPE_MENU) {
ret = -EINVAL;
goto done;
}
if (query_menu->index >= mapping->menu_count) {
ret = -EINVAL;
goto done;
}
menu_info = &mapping->menu_info[query_menu->index];
strlcpy(query_menu->name, menu_info->name, sizeof query_menu->name);
done:
mutex_unlock(&chain->ctrl_mutex);
return ret;
}
/* --------------------------------------------------------------------------
* Control transactions

36
drivers/media/video/uvc/uvc_v4l2.c
View File

@ -100,40 +100,6 @@ done:
* V4L2 interface
*/
/*
* Mapping V4L2 controls to UVC controls can be straighforward if done well.
* Most of the UVC controls exist in V4L2, and can be mapped directly. Some
* must be grouped (for instance the Red Balance, Blue Balance and Do White
* Balance V4L2 controls use the White Balance Component UVC control) or
* otherwise translated. The approach we take here is to use a translation
* table for the controls that can be mapped directly, and handle the others
* manually.
*/
static int uvc_v4l2_query_menu(struct uvc_video_chain *chain,
struct v4l2_querymenu *query_menu)
{
struct uvc_menu_info *menu_info;
struct uvc_control_mapping *mapping;
struct uvc_control *ctrl;
u32 index = query_menu->index;
u32 id = query_menu->id;
ctrl = uvc_find_control(chain, query_menu->id, &mapping);
if (ctrl == NULL || mapping->v4l2_type != V4L2_CTRL_TYPE_MENU)
return -EINVAL;
if (query_menu->index >= mapping->menu_count)
return -EINVAL;
memset(query_menu, 0, sizeof(*query_menu));
query_menu->id = id;
query_menu->index = index;
menu_info = &mapping->menu_info[query_menu->index];
strlcpy(query_menu->name, menu_info->name, sizeof query_menu->name);
return 0;
}
/*
* Find the frame interval closest to the requested frame interval for the
* given frame format and size. This should be done by the device as part of
@ -624,7 +590,7 @@ static long uvc_v4l2_do_ioctl(struct file *file, unsigned int cmd, void *arg)
}
case VIDIOC_QUERYMENU:
return uvc_v4l2_query_menu(chain, arg);
return uvc_query_v4l2_menu(chain, arg);
case VIDIOC_G_EXT_CTRLS:
{

4
drivers/media/video/uvc/uvcvideo.h
View File

@ -606,10 +606,10 @@ extern int uvc_status_suspend(struct uvc_device *dev);
extern int uvc_status_resume(struct uvc_device *dev);
/* Controls */
extern struct uvc_control *uvc_find_control(struct uvc_video_chain *chain,
__u32 v4l2_id, struct uvc_control_mapping **mapping);
extern int uvc_query_v4l2_ctrl(struct uvc_video_chain *chain,
struct v4l2_queryctrl *v4l2_ctrl);
extern int uvc_query_v4l2_menu(struct uvc_video_chain *chain,
struct v4l2_querymenu *query_menu);
extern int uvc_ctrl_add_mapping(struct uvc_video_chain *chain,
const struct uvc_control_mapping *mapping);