From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from mail-ww0-f44.google.com ([74.125.82.44]:65134 "EHLO mail-ww0-f44.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753290Ab1CJTnp (ORCPT ); Thu, 10 Mar 2011 14:43:45 -0500 Received: by wwa36 with SMTP id 36so2358989wwa.1 for ; Thu, 10 Mar 2011 11:43:44 -0800 (PST) Message-ID: <4D7929EC.7080003@gmail.com> Date: Thu, 10 Mar 2011 20:43:40 +0100 From: Sylwester Nawrocki MIME-Version: 1.0 To: jtp.park@samsung.com CC: linux-media@vger.kernel.org, laurent.pinchart@ideasonboard.com Subject: Re: [PATCH/RFC 0/2] Support controls at the subdev file handler level References: <1299706041-21589-1-git-send-email-laurent.pinchart@ideasonboard.com> <000601cbdf09$76be8c10$643ba430$%park@samsung.com> In-Reply-To: <000601cbdf09$76be8c10$643ba430$%park@samsung.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit List-ID: Sender: Hi, On 03/10/2011 10:56 AM, Jeongtae Park wrote: > Hi, all. > > Some hardware need to handle per-filehandle level controls. > Hans suggests add a v4l2_ctrl_handler struct v4l2_fh. It will be work fine. > Although below patch series are for subdev, but it's great start point. > I will try to make a patch. > > If v4l2 control framework can be handle per-filehandle controls, > a driver could be handle per-buffer level controls also. (with VB2 callback > operation) > Can you elaborate to what kind of per buffer controls are you referring to? Using optional meta data planes is expected to be a proper way to do such things. Either to pass meta data from application to driver or in the opposite direction. I can't see how the per buffer controls can be dependent on a per file handle control support. Perhaps this is only specific to some selected devices. -- Regards, Sylwester Nawrocki