From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753931AbaG2Op2 (ORCPT ); Tue, 29 Jul 2014 10:45:28 -0400 Received: from mout.kundenserver.de ([212.227.126.131]:64546 "EHLO mout.kundenserver.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753654AbaG2OpV (ORCPT ); Tue, 29 Jul 2014 10:45:21 -0400 From: Arnd Bergmann To: linux-arm-kernel@lists.infradead.org Cc: Stefan Agner , shawn.guo@freescale.com, kernel@pengutronix.de, peter.chen@freescale.com, linux-kernel@vger.kernel.org, jingchang.lu@freescale.com Subject: Re: [PATCH] ARM: imx: clk-vf610: introduce clks_init_on Date: Tue, 29 Jul 2014 16:44:31 +0200 Message-ID: <2815679.ZycfkLhBgI@wuerfel> User-Agent: KMail/4.11.5 (Linux/3.11.0-23-generic; KDE/4.11.5; x86_64; ; ) In-Reply-To: <1406643628-4061-1-git-send-email-stefan@agner.ch> References: <1406643628-4061-1-git-send-email-stefan@agner.ch> MIME-Version: 1.0 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="us-ascii" X-Provags-ID: V02:K0:DztwL3Tj4qDOFCpMXbmLPLrndaMDtrvF9LEunnerC4y 9l6SlUCkFmohlU+DDd2ao6xEm+sBjGjNMARUoKfF0OXXBTuHZG 6/8TNql1BnMAN9qMuRLQEzJbRlmI7qfzdp2TWv+Hdpzbk+g0pt m4s3zkJYXu60TBWaDrFsyN6Rh4srDh8e/A3/H4nVm531YgTOYm MAyiG0b7U5PpEO2wAyiGKhxmY8vRwuUfaU2EWQBqJN5yW8OjOD neZ1gl3J0C29XVoXE9KXJrbKyLbucVEs+yjyghE996s81xDdnj AHBcqllEyss/E9agkXV3PZN7RIq9g7keh38xJfd/WZbqoUjgVO 2edRtVGJCKrdJOWCizpE= Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tuesday 29 July 2014 16:20:28 Stefan Agner wrote: > At the end of the boot process, the clock framework might disable > required main PLL's. So far, this was no issue since drivers > requested clocks, which are descended of the main PLL's (e.g. > pll1_pfd1, which provides the system clock). > > To archive the full 500MHz system clock, DDR clock need to be a > descendant of PLL2 rather than PLL1 (DDRC_CLK_SEL set to 0). The > bootloader sets up the clocks accordingly before making use of > DDR at all. However, in Linux, there is no driver using PLL2, > which lead to PLL2 being disabled by the clock framework. > > With this patch, we make sure that the main system clock and the > DDR clock are initially enabled and are kept enabled. > > Signed-off-by: Stefan Agner > Wouldn't it be better to list this in the DT as a default for the respective clocks? Arnd