From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stephen Warren Subject: Re: [PATCH] ARM: dts: tegra: move serial aliases to per-board Date: Tue, 11 Nov 2014 14:14:07 -0700 Message-ID: <54627C1F.9050200@wwwdotorg.org> References: <1415738970-7963-1-git-send-email-olof@lixom.net> Mime-Version: 1.0 Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1415738970-7963-1-git-send-email-olof-nZhT3qVonbNeoWH0uzbU5w@public.gmane.org> Sender: linux-tegra-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Olof Johansson , thierry.reding-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org, gnurou-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org Cc: linux-tegra-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org, gregkh-de/tnXTf+JLsfHDXvbKv3WD2FQJk+8+b@public.gmane.org, Laxman Dewangan List-Id: linux-tegra@vger.kernel.org On 11/11/2014 01:49 PM, Olof Johansson wrote: > There are general changes pending to make the /aliases/serial* entries > number the serial ports on the system. On tegra, so far the ports have been > just numbered dynamically as they are configured so that makes them change. > > To avoid this, add specific aliases per board to keep the old numbers. This > allows us to change the numbering by default on future SoCs while keeping the > numbering on existing boards. This change seems mostly OK to me. FWIW though, I had suggested this approach when the UART aliases were first added, and Laxman disagreed with it. See commit b6551bb933f9 "ARM: tegra: dts: add aliases and DMA requestor for serial controller", and its discussion: https://lkml.org/lkml/2012/12/25/4. I've CC'd Laxman in case he still objects. > Signed-off-by: Olof Johansson > --- > > Stephen/Thierry/Alex, as noticed this week we really should try to get > this in before the 3.19 merge window so that the global aliases change > can happen there without regression. How did we resolve the issue that patch causes with old DTs; namely that it causes a change in behaviour for those old DTs? On IRC, I'd wondered whether we should set a flag so the kernel ignored aliases for boards containing currently upstreamed Tegra SoCs so that issue wouldn't occur. If we did that, we wouldn't need this patch.