Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754738AbcDFXPH (ORCPT ); Wed, 6 Apr 2016 19:15:07 -0400 Received: from mail-lf0-f53.google.com ([209.85.215.53]:36469 "EHLO mail-lf0-f53.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754474AbcDFXPE (ORCPT ); Wed, 6 Apr 2016 19:15:04 -0400 Subject: Re: [PATCH] ARM: dts: r8a7791: Don't disable referenced optional clocks To: Sjoerd Simons , Simon Horman References: <1459947173-6664-1-git-send-email-sjoerd.simons@collabora.co.uk> Cc: linux-renesas-soc@vger.kernel.org, devicetree@vger.kernel.org, Geert Uytterhoeven , linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org From: Sergei Shtylyov Organization: Cogent Embedded Message-ID: <57059874.1070309@cogentembedded.com> Date: Thu, 7 Apr 2016 02:15:00 +0300 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.6.0 MIME-Version: 1.0 In-Reply-To: <1459947173-6664-1-git-send-email-sjoerd.simons@collabora.co.uk> Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2017 Lines: 66 On 04/06/2016 03:52 PM, Sjoerd Simons wrote: > clk_get on a disabled clock node will return EPROBE_DEFER, which can > cause drivers to be deferred forever if such clocks are referenced in > their clocks property. > > Update the various disabled external clock nodes to default to a > frequency of 0, but don't disable them to prevent this. > > Signed-off-by: Sjoerd Simons > > --- > > arch/arm/boot/dts/r8a7791-koelsch.dts | 1 + > arch/arm/boot/dts/r8a7791-porter.dts | 1 + > arch/arm/boot/dts/r8a7791.dtsi | 5 +---- > 3 files changed, 3 insertions(+), 4 deletions(-) > > diff --git a/arch/arm/boot/dts/r8a7791-koelsch.dts b/arch/arm/boot/dts/r8a7791-koelsch.dts > index 1adf877..da59c28 100644 > --- a/arch/arm/boot/dts/r8a7791-koelsch.dts > +++ b/arch/arm/boot/dts/r8a7791-koelsch.dts > @@ -660,6 +660,7 @@ > }; > > &pcie_bus_clk { > + clock-frequency = <100000000>; Hmmm, looking at the Koelsch schematics, I don't see this clock. :-/ > status = "okay"; > }; > > diff --git a/arch/arm/boot/dts/r8a7791-porter.dts b/arch/arm/boot/dts/r8a7791-porter.dts > index 9554d13..19b257e 100644 > --- a/arch/arm/boot/dts/r8a7791-porter.dts > +++ b/arch/arm/boot/dts/r8a7791-porter.dts > @@ -413,6 +413,7 @@ > }; > > &pcie_bus_clk { > + clock-frequency = <100000000>; > status = "okay"; > }; > Again, looking at the Porter schematics, I don't see this clock either. :-/ > diff --git a/arch/arm/boot/dts/r8a7791.dtsi b/arch/arm/boot/dts/r8a7791.dtsi > index 8693888..676df63 100644 > --- a/arch/arm/boot/dts/r8a7791.dtsi > +++ b/arch/arm/boot/dts/r8a7791.dtsi > @@ -1104,8 +1104,7 @@ > pcie_bus_clk: pcie_bus { > compatible = "fixed-clock"; > #clock-cells = <0>; > - clock-frequency = <100000000>; > - status = "disabled"; > + clock-frequency = <0>; If the clock has a good default frequency, I don't think you need to remove it. Otherwise you missed USB_EXTAL which is 48 MHz (and can be overridden). [...] MBR, Sergei