From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751654AbaLPXls (ORCPT ); Tue, 16 Dec 2014 18:41:48 -0500 Received: from mail.kmu-office.ch ([178.209.48.109]:53922 "EHLO mail.kmu-office.ch" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751030AbaLPXlq (ORCPT ); Tue, 16 Dec 2014 18:41:46 -0500 MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Date: Wed, 17 Dec 2014 00:41:33 +0100 From: Stefan Agner To: Arnd Bergmann Cc: linux-arm-kernel@lists.infradead.org, shawn.guo@linaro.org, kernel@pengutronix.de, linux@arm.linux.org.uk, u.kleine-koenig@pengutronix.de, jason@lakedaemon.net, olof@lixom.net, daniel.lezcano@linaro.org, tglx@linutronix.de, mark.rutland@arm.com, pawel.moll@arm.com, robh+dt@kernel.org, ijc+devicetree@hellion.org.uk, galak@codeaurora.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 11/12] ARM: dts: add support for Vybrid running on Cortex-M4 In-Reply-To: <2994970.DCfUQgtmcD@wuerfel> References: <1417565531-4507-1-git-send-email-stefan@agner.ch> <1417565531-4507-12-git-send-email-stefan@agner.ch> <2994970.DCfUQgtmcD@wuerfel> Message-ID: <6ae4dd827bf4dcc202f60e8505173d0e@agner.ch> User-Agent: Roundcube Webmail/1.0.3 X-DSPAM-Result: Whitelisted X-DSPAM-Processed: Wed Dec 17 00:40:48 2014 X-DSPAM-Confidence: 0.9899 X-DSPAM-Probability: 0.0000 X-DSPAM-Signature: 5490c30012811615911700 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2014-12-03 12:03, Arnd Bergmann wrote: > On Wednesday 03 December 2014 01:12:10 Stefan Agner wrote: >> diff --git a/arch/arm/boot/dts/vf610m4-colibri.dts b/arch/arm/boot/dts/vf610m4-colibri.dts >> new file mode 100644 >> index 0000000..051ee0f >> --- /dev/null >> +++ b/arch/arm/boot/dts/vf610m4-colibri.dts >> @@ -0,0 +1,52 @@ >> +/* >> + * Device tree for Colibri VF61 Cortex-M4 support >> + * >> + * Copyright 2014 Stefan Agner >> + * >> + * This program is free software; you can redistribute it and/or modify >> + * it under the terms of the GNU General Public License as published by >> + * the Free Software Foundation; either version 2 of the License, or >> + * (at your option) any later version. >> + */ >> + >> +/dts-v1/; >> +#include "vf610m4.dtsi" >> + >> +/ { >> + model = "VF610 Cortex-M4"; >> + compatible = "fsl,vf610m4"; >> + >> + chosen { >> + bootargs = "console=ttyLP2,115200 ihash_entries=64 dhash_entries=64 earlyprintk clk_ignore_unused init=/linuxrc rw"; >> + }; >> + > > Starting with v3.19, you should be able to use the earlycon framework on > arm32, so it would be better to replace earlyprintk with earlycon here > and add a stdout-path property in chosen that points to the console > uart. I started to implement earlycon support, but something currently fails when earlycon tries to map the UART registers: [ 0.000000] earlycon_map: Couldn't map 0x40027000 I traced the issue a bit further down and found that get_vm_area_caller returns NULL (in __arm_ioremap_pfn_caller). This happend on Linus master as of today (2dbfca5a181973558277b28b1f4c36362291f5e0). Do I miss something here? > > 64 hash table entries sounds extremely small, doesn't that impact > performance? If you have 50MB of actual RAM available, I don't think > you need that. > > Arnd From mboxrd@z Thu Jan 1 00:00:00 1970 From: stefan@agner.ch (Stefan Agner) Date: Wed, 17 Dec 2014 00:41:33 +0100 Subject: [PATCH 11/12] ARM: dts: add support for Vybrid running on Cortex-M4 In-Reply-To: <2994970.DCfUQgtmcD@wuerfel> References: <1417565531-4507-1-git-send-email-stefan@agner.ch> <1417565531-4507-12-git-send-email-stefan@agner.ch> <2994970.DCfUQgtmcD@wuerfel> Message-ID: <6ae4dd827bf4dcc202f60e8505173d0e@agner.ch> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On 2014-12-03 12:03, Arnd Bergmann wrote: > On Wednesday 03 December 2014 01:12:10 Stefan Agner wrote: >> diff --git a/arch/arm/boot/dts/vf610m4-colibri.dts b/arch/arm/boot/dts/vf610m4-colibri.dts >> new file mode 100644 >> index 0000000..051ee0f >> --- /dev/null >> +++ b/arch/arm/boot/dts/vf610m4-colibri.dts >> @@ -0,0 +1,52 @@ >> +/* >> + * Device tree for Colibri VF61 Cortex-M4 support >> + * >> + * Copyright 2014 Stefan Agner >> + * >> + * This program is free software; you can redistribute it and/or modify >> + * it under the terms of the GNU General Public License as published by >> + * the Free Software Foundation; either version 2 of the License, or >> + * (at your option) any later version. >> + */ >> + >> +/dts-v1/; >> +#include "vf610m4.dtsi" >> + >> +/ { >> + model = "VF610 Cortex-M4"; >> + compatible = "fsl,vf610m4"; >> + >> + chosen { >> + bootargs = "console=ttyLP2,115200 ihash_entries=64 dhash_entries=64 earlyprintk clk_ignore_unused init=/linuxrc rw"; >> + }; >> + > > Starting with v3.19, you should be able to use the earlycon framework on > arm32, so it would be better to replace earlyprintk with earlycon here > and add a stdout-path property in chosen that points to the console > uart. I started to implement earlycon support, but something currently fails when earlycon tries to map the UART registers: [ 0.000000] earlycon_map: Couldn't map 0x40027000 I traced the issue a bit further down and found that get_vm_area_caller returns NULL (in __arm_ioremap_pfn_caller). This happend on Linus master as of today (2dbfca5a181973558277b28b1f4c36362291f5e0). Do I miss something here? > > 64 hash table entries sounds extremely small, doesn't that impact > performance? If you have 50MB of actual RAM available, I don't think > you need that. > > Arnd