From mboxrd@z Thu Jan 1 00:00:00 1970 From: Guennadi Liakhovetski Subject: Re: [PATCH 07/14] media: soc-camera: support deferred probing of clients Date: Wed, 10 Apr 2013 16:43:21 +0200 (CEST) Message-ID: References: <1348754853-28619-1-git-send-email-g.liakhovetski@gmx.de> <1348754853-28619-8-git-send-email-g.liakhovetski@gmx.de> Mime-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Return-path: In-Reply-To: Sender: linux-media-owner@vger.kernel.org To: Barry Song <21cnbao@gmail.com> Cc: Sylwester Nawrocki , Mark Brown , linux-media@vger.kernel.org, linux-sh@vger.kernel.org, devicetree-discuss@lists.ozlabs.org, Magnus Damm , Hans Verkuil , Laurent Pinchart , "renwei.wu" , DL-SHA-WorkGroupLinux , xiaomeng.hou@csr.com, zilong.wu@csr.com List-Id: devicetree@vger.kernel.org On Wed, 10 Apr 2013, Barry Song wrote: > 2013/4/10 Guennadi Liakhovetski : > > On Wed, 10 Apr 2013, Barry Song wrote: [snip] > >> > This cannot work, because some I2C devices, e.g. sensors, need a clock > >> > signal from the camera interface to probe. Before the bridge driver has > >> > completed its probing and registered a suitable clock source with the > >> > v4l2-clk framework, sensors cannot be probed. And no, we don't want to > >> > fake successful probing without actually being able to talk to the > >> > hardware. > >> > >> i'd say same dependency also exists on ASoC. a "fake" successful > >> probing doesn't mean it should really begin to work if there is no > >> external trigger source. ASoC has successfully done that by a machine > >> driver to connect all DAI. > >> a way is we put all things ready in their places, finally we connect > >> them together and launch the whole hardware flow. > >> > >> anyway, if you have maken the things work by some simple hacking and > >> that means minimial changes to current soc-camera, i think we can > >> follow. > > > > If you want to volunteer to step up as a new soc-camera maintainer to > > replace my simple hacking with your comprehencive and advanced designs - > > feel free, I'll ack straight away. > > i am not sure whether you agree the new way or not. if you also agree > this is a better way, In fact I don't. > i think we can do something to move ahead. i > need sync and get input from you expert :-) I suggest you read all the mailing list discussions of these topics over last months / years, conference discussion protocols instead of restarting a beaten to death topic at the v8 time-frame. Thanks Guennadi --- Guennadi Liakhovetski, Ph.D. Freelance Open-Source Software Developer http://www.open-technology.de/