From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from protonic.xs4all.nl ([83.163.252.89] helo=protonic.nl) by bombadil.infradead.org with esmtp (Exim 4.90_1 #2 (Red Hat Linux)) id 1fSjcq-0003LP-RI for barebox@lists.infradead.org; Tue, 12 Jun 2018 13:46:22 +0000 Date: Tue, 12 Jun 2018 15:46:06 +0200 From: David Jander Message-ID: <20180612154606.4b41d063@erd980> In-Reply-To: <20180612124738.pi66gx2vlgvoljmo@pengutronix.de> References: <20180612142308.4a048a14@erd980> <20180612124738.pi66gx2vlgvoljmo@pengutronix.de> MIME-Version: 1.0 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: Device-tree node renames break barebox/kernel compatibility... To: Sascha Hauer Cc: Fabio Estevam , Barebox List , Marco Franchi , Shawn Guo On Tue, 12 Jun 2018 14:47:38 +0200 Sascha Hauer wrote: > Hi David, > > On Tue, Jun 12, 2018 at 02:23:08PM +0200, David Jander wrote: > > > > Hi Sascha, > > > > I know this is old already, and I was surprised that I couldn't find any > > complaints about this yet, but I recently came across this patch in the kernel: > > > > https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/patch/?id=df5cc9d0b42d15fa33b30440cca7a11ca7ba35a4 > > > > ...which was adopted in barebox as this: > > > > https://git.pengutronix.de/cgit/barebox/patch/dts/src/arm/imx6qdl.dtsi?id=2e9cce8fb1f577088e2b20ae2f461130e13ad190 > > > > As I don't know the exact reason as to why this was necessary, or why this is > > an issue at all, I just wanted to point out the fact that this leads to some > > breakage in barebox new and old. > > This issue is known and has led to > https://www.mail-archive.com/barebox@lists.infradead.org/msg25189.html Ah, thanks for the pointer. I had searched through the list archive since september-2017 and did not find this... need new glasses anyway. > > > > The specific problem I observed is here: > > https://git.pengutronix.de/cgit/barebox/tree/net/eth.c#n299 > > of_get_reproducible_name()/of_find_node_by_reproducible_name() is used for > fixing up mtd partitions and state nodes, but not yet for the ethernet > devices because nobody noticed. > > To fix you would have to get a reproducible name of the ethernet device > node from the barebox device tree using of_find_node_by_reproducible_name() > and then use of_find_node_by_reproducible_name() on the kernel device > tree. Ok, this makes sense. My only grief is that we are still left with a forced bootloader update before being able to move to kernel 4.15+, for a reason which to me doesn't sound really worth it. Granted, the leading zero's are a bit ugly and probably never should have made it mainline, but I don't understand why the DT compiler should suddenly complain about that and can't be fixed. In a way, the device-tree is an interface from the kernel to the outside world, and while it is not really "user-space", IMHO it should still be regarded stable and "set in stone"... but maybe that's just me? Of course if it really _is_ structurally wrong, it must be fixed, but please be aware that it _will_ hurt people! >From a manufacturer perspective, I can say that while customers have come to accept regular kernel updates (due to legitimate security reasons and whatnot), bootloader upgrades are still a big issue. They usually don't accept such "risky" upgrades in the field without putting up a fight :-( Best regards, -- David Jander Protonic Holland. _______________________________________________ barebox mailing list barebox@lists.infradead.org http://lists.infradead.org/mailman/listinfo/barebox