Hi Mauro, On Monday 22 February 2010 22:14:19 Patch from Laurent Pinchart wrote: > From: Laurent Pinchart <laurent.pinch...@ideasonboard.com> > MIME-Version: 1.0 > Content-Type: text/plain; charset=utf-8 > Content-Transfer-Encoding: 8bit
There's a problem somewhere. > 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.pinch...@ideasonboard.com> > Tested-by: Márton Németh <nm...@freemail.hu> > Signed-off-by: Mauro Carvalho Chehab <mche...@redhat.com> > > drivers/media/video/uvc/uvc_ctrl.c | 47 > ++++++++++++++++++++++++++++++++--- drivers/media/video/uvc/uvc_v4l2.c | > 2 + > 2 files changed, 45 insertions(+), 4 deletions(-) > > --- > > http://git.linuxtv.org/v4l-dvb.git?a=commitdiff;h=a8677cd5589be9e35ef5117f7 > 5e4b996724102fb > > diff --git a/drivers/media/video/uvc/uvc_ctrl.c > b/drivers/media/video/uvc/uvc_ctrl.c index 5ff5013..f38bc6b 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 23239a4..bf1fc7f 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; > } -- Regards, Laurent Pinchart -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
