From mboxrd@z Thu Jan 1 00:00:00 1970 From: Arnd Bergmann Subject: Re: [PATCH v4 2/8] arm64: dts: exynos: Add dts files for 64-bit Exynos5433 SoC Date: Wed, 04 Mar 2015 10:38:06 +0100 Message-ID: <2449954.zWisnqDpUA@wuerfel> References: <1424755011-15999-1-git-send-email-cw00.choi@samsung.com> <13467157.nyRCsNWIp6@wuerfel> <54F6AD6B.70007@samsung.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7Bit Return-path: In-Reply-To: <54F6AD6B.70007@samsung.com> Sender: linux-kernel-owner@vger.kernel.org To: Chanwoo Choi Cc: Chanwoo Choi , linux-arm-kernel , Mark Rutland , devicetree , linux-samsung-soc , Marc Zyngier , "catalin.marinas@arm.com" , Olof Johansson , "will.deacon@arm.com" , linux-kernel , "jh80.chung@samsung.com" , Seung-Woo Kim , Kukjin Kim , Abhilash Kesavan , "chanho61.park@samsung.com" , "inki.dae@samsung.com" , ideal.song@samsung.com List-Id: devicetree@vger.kernel.org On Wednesday 04 March 2015 15:59:55 Chanwoo Choi wrote: > On 03/02/2015 06:22 AM, Arnd Bergmann wrote: > > On Saturday 28 February 2015 09:47:01 Chanwoo Choi wrote: > >> "earlycon=exynos4210,0x14C20000" is correct bootparam. You can check > >> it on Documentation/kernel-parameters.txt as following. > >> > >> exynos4210, > >> Use early console provided by serial driver available > >> on Samsung SoCs, requires selecting proper type and > >> a correct base address of the selected UART port. The > >> serial port must already be setup and configured. > >> Options are not yet supported. > >> > >> > > > > But it's crazy to do this when you have a DT. Please fix the existing > > devicetree files that use this to just list 'earlycon'. > > > > The syntax above only makes sense for classic board files that we > > do not support for exynos any more. > > Following earlycon patch for exynos soc was merged in Linux 4.0-rc1. > - commit-id: b94ba0328d3b36ff95f5074c0e9b44f90dc56bb5 (serial: samsung: Add support for early console) > Almost Exynos SoC use the same UART IP of Exynos4210. > > If you mean that "earlycon=exynos4210" naming will be changed to "earlycon=exynos", > we have to modify the drivers/tty/serial/samsung.c. No, what I mean is that you should use just "earlycon" instead of "earlycon=..." when you have a DTB. You have the OF_EARLYCON_DECLARE() in the driver as well, so that should just work. EARLYCON_DECLARE() is really just a hack that allows users to override the early console from the command line without modifying the stdout-path property. Don't put that into a dts file. Arnd