From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from metis.ext.pengutronix.de ([2001:67c:670:201:290:27ff:fe1d:cc33]) by bombadil.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1aGMrf-0006ku-CB for barebox@lists.infradead.org; Tue, 05 Jan 2016 08:21:12 +0000 Date: Tue, 5 Jan 2016 09:20:48 +0100 From: Sascha Hauer Message-ID: <20160105082048.GQ13058@pengutronix.de> References: <1450484040.26955.228.camel@rtred1test09.kymeta.local> <20160104083257.GA13058@pengutronix.de> <1451934452.26955.281.camel@rtred1test09.kymeta.local> <20160105075831.GO13058@pengutronix.de> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "barebox" Errors-To: barebox-bounces+u.kleine-koenig=pengutronix.de@lists.infradead.org Subject: Re: [PATCH 1/2] of: Add for_each_compatible_node_from iterator To: Yegor Yefremov Cc: barebox , Trent Piepho On Tue, Jan 05, 2016 at 09:05:35AM +0100, Yegor Yefremov wrote: > On Tue, Jan 5, 2016 at 8:58 AM, Sascha Hauer wrote: > > On Mon, Jan 04, 2016 at 07:07:27PM +0000, Trent Piepho wrote: > >> On Mon, 2016-01-04 at 09:32 +0100, Sascha Hauer wrote: > >> > On Sat, Dec 19, 2015 at 12:13:59AM +0000, Trent Piepho wrote: > >> > > The existing iterator for_each_compatible_node() searches for each > >> > > compatible node starting from the root of the loaded device tree. > >> > > This means it only works on the barebox device tree and not the tree > >> > > to be passed to the Linux kernel, which is what an of_fixup would > >> > > probably want to use. > >> > > > >> > > This adds for_each_compatible_node_from(), which takes an additional > >> > > parameter of a root to search from. This could be the device tree to > >> > > be used for the kernel. It could also be used to search just a > >> > > subtree. > >> > > > >> > > Signed-off-by: Trent Piepho > >> > > >> > Applied, thanks > >> > > >> > > --- > >> > > > >> > > It's possible the fixups in cm_cogent_fixup() and hb_fixup() should > >> > > be using this. It's not clear to me if they want to modify the barebox > >> > > device tree or the Linux device tree or both. > >> > > >> > It's always the Linux device tree that is fixed up in the OF fixups. > >> > >> Sent patch to fix them. > >> > >> Couldn't one also use the of fixup system to modify the barebox DT? In > >> order to support multiple board variants, I added DT nodes that specify > >> what nodes should be enabled and/or disabled for different board > >> versions. An OF fixup applies this to the Linux DT. I haven't had to > >> modify the barebox DT for different boards but anticipate that happening > >> for the next board and I was planning to use the same system. > > > > I think you don't need the fixup system to accomplish that. Just hook up > > to an initcall early enough and modify the barebox device tree. It > > shouldn't be necessary to register a callback first and then wait for > > its execution. > > What initcall can be used to change the device tree, that is already > loaded into memory and before Linux is started? You want to change the device tree that is passed to Linux, right? In this case you can use of_register_fixup(). We were talking about changing the device tree that barebox uses for itself. For this everything after core_initcall will work. It should be early enough though so that the device that is ought to be changed has not probed, so I suggest doing it as early as possible, that would be postcore_initcall. Sascha -- Pengutronix e.K. | | Industrial Linux Solutions | http://www.pengutronix.de/ | Peiner Str. 6-8, 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 | Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 | _______________________________________________ barebox mailing list barebox@lists.infradead.org http://lists.infradead.org/mailman/listinfo/barebox