From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from mail-vx0-f174.google.com ([209.85.220.174]:56149 "EHLO mail-vx0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752543Ab1I0KAE (ORCPT ); Tue, 27 Sep 2011 06:00:04 -0400 Received: by vcbfk10 with SMTP id fk10so3482920vcb.19 for ; Tue, 27 Sep 2011 03:00:03 -0700 (PDT) MIME-Version: 1.0 In-Reply-To: <201109271142.41309.hverkuil@xs4all.nl> References: <1316465981-28469-1-git-send-email-scott.jiang.linux@gmail.com> <201109261609.32349.hverkuil@xs4all.nl> <201109271142.41309.hverkuil@xs4all.nl> Date: Tue, 27 Sep 2011 18:00:03 +0800 Message-ID: Subject: Re: [PATCH 4/4 v2][FOR 3.1] v4l2: add blackfin capture bridge driver From: Scott Jiang To: Hans Verkuil Cc: Mauro Carvalho Chehab , Laurent Pinchart , Guennadi Liakhovetski , linux-media@vger.kernel.org, uclinux-dist-devel@blackfin.uclinux.org Content-Type: text/plain; charset=ISO-8859-1 Sender: linux-media-owner@vger.kernel.org List-ID: > > What you would typically do in a case like this (if I understand it > correctly) is that in the s_input ioctl you first select the input in the > subdev, and then you can call the subdev to determine the standard and > format and use that information to set up the bridge. This requires that > the subdev is able to return a proper standard/format after an input > change. > > By also selecting an initial input at driver load you will ensure that > you always have a default std/fmt available from the very beginning. > The default input is 0. So you mean I ask the subdev std and fmt in probe instead of open? > It also looks like the s_input in the bridge driver allows for inputs that > return a subdev format that can't be supported by the bridge. Is that correct? > If so, then the board code should disallow such inputs. Frankly, that's a > WARN_ON since that is something that is never supposed to happen.