From mboxrd@z Thu Jan 1 00:00:00 1970 From: Barry Song <21cnbao@gmail.com> Subject: Re: [PATCH 07/14] media: soc-camera: support deferred probing of clients Date: Wed, 10 Apr 2013 23:02:08 +0800 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=UTF-8 Return-path: In-Reply-To: Sender: linux-sh-owner@vger.kernel.org To: Guennadi Liakhovetski 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 2013/4/10 Guennadi Liakhovetski : > 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. you think it has been dead but i think it is still alive since there are still sombody like me starting a beaten for that. anyway, it doesn't really matter too much. i can definitely follow what you like as you have succefully built a good soc-camera system. > > Thanks > Guennadi > --- > Guennadi Liakhovetski, Ph.D. > Freelance Open-Source Software Developer > http://www.open-technology.de/ -barry