From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from mail-wi0-f179.google.com ([209.85.212.179]:34643 "EHLO mail-wi0-f179.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753405AbaGHSJv (ORCPT ); Tue, 8 Jul 2014 14:09:51 -0400 Received: by mail-wi0-f179.google.com with SMTP id cc10so1473024wib.0 for ; Tue, 08 Jul 2014 11:09:50 -0700 (PDT) Message-ID: <53BC342B.4070801@googlemail.com> Date: Tue, 08 Jul 2014 20:10:51 +0200 From: =?UTF-8?B?RnJhbmsgU2Now6RmZXI=?= MIME-Version: 1.0 To: Rafael Coutinho , linux-media@vger.kernel.org Subject: Re: New v4l2 driver does not allow brightness/contrast control References: In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-media-owner@vger.kernel.org List-ID: Am 07.07.2014 19:58, schrieb Rafael Coutinho: > I have a v4l2 video capture board that using kernel 2.6 with v4l2 > em28xx driver 3.0.36 allows me to control brightness, contrast etc... > However in kernel 3.2 with v4l2 em28xx driver version 3.2.0 it does not. > > This is what I get from the latest driver: > root@android:/ # v4l2-ctl --info > Driver Info (not using libv4l2): > Driver name : em28xx > Card type : EM2860/SAA711X Reference Design > Bus info : usb-musb-hdrc.1-1 > Driver version: 3.2.0 > Capabilities : 0x05020051 > Video Capture > VBI Capture > Sliced VBI Capture > Audio > Read/Write > Streaming > root@android:/ # v4l2-ctl -d 0 -l > volume (int) : min=0 max=31 step=1 > default=31 value=31 flags=slider > mute (bool) : default=1 value=1 > > > What could be wrong? Before kernel 3.10, the brightness (contrast, ...) controls are provided by the subdevice drivers. With kernel 3.10 I have introduced bridge level image controls, but they are currently only used/activated if the subdevice doesn't already provide them (as suggested by Mauro). Hth, Frank Schäfer