From mboxrd@z Thu Jan 1 00:00:00 1970 From: Sylwester Nawrocki Subject: Re: [PATCH] ARM: dts: Specify default clocks for Exynos4 FIMC devices Date: Fri, 26 Sep 2014 15:45:09 +0200 Message-ID: <54256DE5.5050203@samsung.com> References: <1410367054-30926-1-git-send-email-s.nawrocki@samsung.com> <5424900D.2070709@gmail.com> <54254776.7070803@samsung.com> <5425690A.6080102@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Return-path: Received: from mailout4.w1.samsung.com ([210.118.77.14]:23196 "EHLO mailout4.w1.samsung.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752149AbaIZNpZ (ORCPT ); Fri, 26 Sep 2014 09:45:25 -0400 Received: from eucpsbgm2.samsung.com (unknown [203.254.199.245]) by mailout4.w1.samsung.com (Oracle Communications Messaging Server 7u4-24.01(7.0.4.24.0) 64bit (built Nov 17 2011)) with ESMTP id <0NCI005GFH0B7H60@mailout4.w1.samsung.com> for linux-samsung-soc@vger.kernel.org; Fri, 26 Sep 2014 14:48:11 +0100 (BST) In-reply-to: <5425690A.6080102@gmail.com> Sender: linux-samsung-soc-owner@vger.kernel.org List-Id: linux-samsung-soc@vger.kernel.org To: Tomasz Figa Cc: kgene.kim@samsung.com, linux-arm-kernel@lists.infradead.org, linux-samsung-soc@vger.kernel.org, m.szyprowski@samsung.com On 26/09/14 15:24, Tomasz Figa wrote: > I'm not concerned specifically with Exynos4210, but with placing such > kind of data in common dtsi files. > > Notice that even on boards which have correct initialization done by > firmware, this will cause the settings to be overwritten, even if the > firmware sets correct, but different values, regardless of them being > clock parents or rates. > > To me, even if this would mean duplicating some data, making this per > board and present only in dts files of boards that actually need this > (i.e. are known to have broken firmware) sounds more reasonable. OTOH by having those settings in device tree would ensure the clock tree is set correctly, regardless of the firmware. There is only one correct clock parent for these devices, so the kernel couldn't do any harm. I'd say it never worked in practice to rely on the bootloader to configure these things, and one could say the firmware has been broken in general with regards to this issue. -- Regards, Sylwester From mboxrd@z Thu Jan 1 00:00:00 1970 From: s.nawrocki@samsung.com (Sylwester Nawrocki) Date: Fri, 26 Sep 2014 15:45:09 +0200 Subject: [PATCH] ARM: dts: Specify default clocks for Exynos4 FIMC devices In-Reply-To: <5425690A.6080102@gmail.com> References: <1410367054-30926-1-git-send-email-s.nawrocki@samsung.com> <5424900D.2070709@gmail.com> <54254776.7070803@samsung.com> <5425690A.6080102@gmail.com> Message-ID: <54256DE5.5050203@samsung.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On 26/09/14 15:24, Tomasz Figa wrote: > I'm not concerned specifically with Exynos4210, but with placing such > kind of data in common dtsi files. > > Notice that even on boards which have correct initialization done by > firmware, this will cause the settings to be overwritten, even if the > firmware sets correct, but different values, regardless of them being > clock parents or rates. > > To me, even if this would mean duplicating some data, making this per > board and present only in dts files of boards that actually need this > (i.e. are known to have broken firmware) sounds more reasonable. OTOH by having those settings in device tree would ensure the clock tree is set correctly, regardless of the firmware. There is only one correct clock parent for these devices, so the kernel couldn't do any harm. I'd say it never worked in practice to rely on the bootloader to configure these things, and one could say the firmware has been broken in general with regards to this issue. -- Regards, Sylwester