From mboxrd@z Thu Jan 1 00:00:00 1970 From: Arnd Bergmann Subject: Re: [PATCH] arm/tegra: select AUTO_ZRELADDR by default Date: Fri, 14 Oct 2011 18:27:53 +0200 Message-ID: <201110141827.53906.arnd@arndb.de> References: <1317172068-14872-1-git-send-email-pdeschrijver@nvidia.com> <201110141729.41515.arnd@arndb.de> <74CDBE0F657A3D45AFBB94109FB122FF173BE1A283@HQMAIL01.nvidia.com> Mime-Version: 1.0 Content-Type: Text/Plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <74CDBE0F657A3D45AFBB94109FB122FF173BE1A283-C7FfzLzN0UxDw2glCA4ptUEOCMrvLtNR@public.gmane.org> Sender: linux-tegra-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Stephen Warren Cc: Russell King - ARM Linux , Olof Johansson , Peter De Schrijver , "linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" , "linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org" , "linux-tegra-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" , "Colin Cross (ccross-z5hGa2qSFaRBDgjK7y7TUQ@public.gmane.org)" , Erik Gilling List-Id: linux-tegra@vger.kernel.org On Friday 14 October 2011, Stephen Warren wrote: > Arnd Bergmann wrote at Friday, October 14, 2011 9:30 AM: > ... > > You mention that tegra30 will require AUTO_ZRELADDR. > > Well, just to be clear, here's the situation I think: > > Tegra20's SDRAM starts at physical address 0. > > Tegra30's SDRAM starts at physical address 2G. > > To support that, we could either: > > a) Introduce a new Kconfig variable for Tegra30, make T20/T30 mutually > exclusive, and update arch/arm/mach-tegra/Makefile.boot to set zreladdr > etc. based on the new Tegra30 config variable too. Then, there's no need > for AUTO_ZRELADDR anywhere. > > b) Have no new config variable, build a unified T20/T30 kernel, leave > Makefile.boot untouched, and rely on using AUTO_ZRELADDR for Tegra30 to > account for the different SDRAM physical addresses. Ok, thanks for the explanation, that makes it much clearer. For completeness, you could also do both of the above and make T20/T30 mutually exclusive unless AUTO_ZRELADDR is set. That might be more complex than necessary, I don't know. Arnd