From mboxrd@z Thu Jan 1 00:00:00 1970 From: Laurent Pinchart Subject: Re: [RFC PATCH] [media]: of: move graph helpers from drivers/media/v4l2-core to drivers/of Date: Thu, 20 Mar 2014 19:50:35 +0100 Message-ID: <13435143.OQHHLITVrH@avalon> References: <1392119105-25298-1-git-send-email-p.zabel@pengutronix.de> <2161777.L3ZZmhyfM4@avalon> <20140320181820.GY7528@n2100.arm.linux.org.uk> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7Bit Return-path: In-Reply-To: <20140320181820.GY7528-l+eeeJia6m9vn6HldHNs0ANdhmdF6hFW@public.gmane.org> Sender: devicetree-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Russell King - ARM Linux Cc: Grant Likely , Tomi Valkeinen , Philipp Zabel , Sascha Hauer , Rob Herring , Mauro Carvalho Chehab , Rob Herring , Sylwester Nawrocki , Kyungmin Park , "linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" , "linux-media-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" , "devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" , Philipp Zabel List-Id: devicetree@vger.kernel.org Hi Russell, On Thursday 20 March 2014 18:18:20 Russell King - ARM Linux wrote: > On Thu, Mar 20, 2014 at 07:16:29PM +0100, Laurent Pinchart wrote: > > On Thursday 20 March 2014 17:54:31 Grant Likely wrote: > > > On Wed, 12 Mar 2014 10:25:56 +0000, Russell King - ARM Linux wrote: [snip] > > > > I believe trying to do this according to the flow of data is just > > > > wrong. You should always describe things from the primary device for > > > > the CPU towards the peripheral devices and never the opposite > > > > direction. > > > > > > Agreed. > > > > Absolutely not agreed. The whole concept of CPU towards peripherals only > > makes sense for very simple devices and breaks as soon as the hardware > > gets more complex. There's no such thing as CPU towards peripherals when > > peripherals communicate directly. > > > > Please consider use cases more complex than just a display controller and > > an encoder, and you'll realize how messy not being able to parse the > > whole graph at once will become. Let's try to improve things, not to make > > sure to prevent support for future devices. > > That's odd, I did. > > Please draw some (ascii) diagrams of the situations you're saying this > won't work for, because at the moment all I'm seeing is some vague > hand-waving rather than anything factual that I can relate to. Help > us to actually _see_ the problem you have with this approach so we can > understand it. Working on it. Given my drawing skills this will take a bit of time. -- Regards, Laurent Pinchart -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html