From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from mx1.redhat.com ([209.132.183.28]:32618 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1759809Ab2EKN5K (ORCPT ); Fri, 11 May 2012 09:57:10 -0400 Message-ID: <4FAD1AB8.5010103@redhat.com> Date: Fri, 11 May 2012 15:57:12 +0200 From: Hans de Goede MIME-Version: 1.0 To: Laurent Pinchart CC: linux-media@vger.kernel.org Subject: Re: [PATCH] uvcvideo: Fix V4L2 button controls that share the same UVC control References: <1336744559-9247-1-git-send-email-laurent.pinchart@ideasonboard.com> In-Reply-To: <1336744559-9247-1-git-send-email-laurent.pinchart@ideasonboard.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-media-owner@vger.kernel.org List-ID: looks good, ack. Acked-by: Hans de Goede On 05/11/2012 03:55 PM, Laurent Pinchart wrote: > The Logitech pan/tilt reset UVC control contains two V4L2 button > controls to reset pan and tilt. As the UVC control is not marked as > auto-update, the button bits are set but never reset. A pan reset that > follows a tilt reset would thus reset both pan and tilt. > > Fix this by not caching the control value of write-only controls. All > standard UVC controls are either readable or auto-update, so this will > not cause any regression and will not result in extra USB requests. > > Reported-by: Hans de Goede > Signed-off-by: Laurent Pinchart > --- > drivers/media/video/uvc/uvc_ctrl.c | 7 +++++-- > 1 files changed, 5 insertions(+), 2 deletions(-) > > diff --git a/drivers/media/video/uvc/uvc_ctrl.c b/drivers/media/video/uvc/uvc_ctrl.c > index 28363b7..3bc119b 100644 > --- a/drivers/media/video/uvc/uvc_ctrl.c > +++ b/drivers/media/video/uvc/uvc_ctrl.c > @@ -1348,9 +1348,12 @@ static int uvc_ctrl_commit_entity(struct uvc_device *dev, > > /* Reset the loaded flag for auto-update controls that were > * marked as loaded in uvc_ctrl_get/uvc_ctrl_set to prevent > - * uvc_ctrl_get from using the cached value. > + * uvc_ctrl_get from using the cached value, and for write-only > + * controls to prevent uvc_ctrl_set from setting bits not > + * explicitly set by the user. > */ > - if (ctrl->info.flags& UVC_CTRL_FLAG_AUTO_UPDATE) > + if (ctrl->info.flags& UVC_CTRL_FLAG_AUTO_UPDATE || > + !(ctrl->info.flags& UVC_CTRL_FLAG_GET_CUR)) > ctrl->loaded = 0; > > if (!ctrl->dirty)