From mboxrd@z Thu Jan 1 00:00:00 1970 From: Guennadi Liakhovetski Date: Fri, 05 Oct 2012 11:35:03 +0000 Subject: Re: [PATCH 05/14] media: add a V4L2 OF parser Message-Id: List-Id: References: <1348754853-28619-1-git-send-email-g.liakhovetski@gmx.de> <201210051241.52205.hverkuil@xs4all.nl> <201210051323.45571.hverkuil@xs4all.nl> In-Reply-To: <201210051323.45571.hverkuil@xs4all.nl> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Hans Verkuil Cc: Sylwester Nawrocki , Sylwester Nawrocki , linux-media@vger.kernel.org, devicetree-discuss@lists.ozlabs.org, Laurent Pinchart , Magnus Damm , linux-sh@vger.kernel.org, Mark Brown , Stephen Warren , Arnd Bergmann , Grant Likely On Fri, 5 Oct 2012, Hans Verkuil wrote: > On Fri October 5 2012 12:58:21 Guennadi Liakhovetski wrote: > > On Fri, 5 Oct 2012, Hans Verkuil wrote: [snip] > > > One area that I do not yet completely understand is the i2c bus notifications > > > (or asynchronous loading or i2c modules). > > > > > > I would have expected that using OF the i2c devices are still initialized > > > before the host/bridge driver is initialized. But I gather that's not the > > > case? > > > > No, it's not. I'm not sure, whether it depends on the order of devices in > > the .dts, but, I think, it's better to not have to mandate a certain order > > and I also seem to have seen devices being registered in different order > > with the same DT, but I'm not 100% sure about that. > > > > > If this deferred probing is a general problem, then I think we need a general > > > solution as well that's part of the v4l2 core. > > > > That can be done, perhaps. But we can do it as a next step. As soon as > > we're happy with the OF implementation as such, we can commit that, > > possibly leaving soc-camera patches out for now, then we can think where > > to put async I2C handling. > > It would be good to have a number of 'Reviewed-by's or 'Acked-by's for the > DT binding documentation at least before it is merged. Definitely, I'm sure you'll be honoured to be the first one in the list;-) > I think the soc_camera patches should be left out for now. I suspect that > by adding core support for async i2c handling first, the soc_camera patches > will become a lot easier to understand. Ok, we can do this. Thanks Guennadi --- Guennadi Liakhovetski, Ph.D. Freelance Open-Source Software Developer http://www.open-technology.de/ From mboxrd@z Thu Jan 1 00:00:00 1970 From: Guennadi Liakhovetski Subject: Re: [PATCH 05/14] media: add a V4L2 OF parser Date: Fri, 5 Oct 2012 13:35:03 +0200 (CEST) Message-ID: References: <1348754853-28619-1-git-send-email-g.liakhovetski@gmx.de> <201210051241.52205.hverkuil@xs4all.nl> <201210051323.45571.hverkuil@xs4all.nl> Mime-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Return-path: In-Reply-To: <201210051323.45571.hverkuil@xs4all.nl> Sender: linux-sh-owner@vger.kernel.org To: Hans Verkuil Cc: Sylwester Nawrocki , Sylwester Nawrocki , linux-media@vger.kernel.org, devicetree-discuss@lists.ozlabs.org, Laurent Pinchart , Magnus Damm , linux-sh@vger.kernel.org, Mark Brown , Stephen Warren , Arnd Bergmann , Grant Likely List-Id: devicetree@vger.kernel.org On Fri, 5 Oct 2012, Hans Verkuil wrote: > On Fri October 5 2012 12:58:21 Guennadi Liakhovetski wrote: > > On Fri, 5 Oct 2012, Hans Verkuil wrote: [snip] > > > One area that I do not yet completely understand is the i2c bus notifications > > > (or asynchronous loading or i2c modules). > > > > > > I would have expected that using OF the i2c devices are still initialized > > > before the host/bridge driver is initialized. But I gather that's not the > > > case? > > > > No, it's not. I'm not sure, whether it depends on the order of devices in > > the .dts, but, I think, it's better to not have to mandate a certain order > > and I also seem to have seen devices being registered in different order > > with the same DT, but I'm not 100% sure about that. > > > > > If this deferred probing is a general problem, then I think we need a general > > > solution as well that's part of the v4l2 core. > > > > That can be done, perhaps. But we can do it as a next step. As soon as > > we're happy with the OF implementation as such, we can commit that, > > possibly leaving soc-camera patches out for now, then we can think where > > to put async I2C handling. > > It would be good to have a number of 'Reviewed-by's or 'Acked-by's for the > DT binding documentation at least before it is merged. Definitely, I'm sure you'll be honoured to be the first one in the list;-) > I think the soc_camera patches should be left out for now. I suspect that > by adding core support for async i2c handling first, the soc_camera patches > will become a lot easier to understand. Ok, we can do this. Thanks Guennadi --- Guennadi Liakhovetski, Ph.D. Freelance Open-Source Software Developer http://www.open-technology.de/