From patchwork Wed Jan 26 18:32:50 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Michael Srba X-Patchwork-Id: 536838 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id A4DFEC63682 for ; Wed, 26 Jan 2022 18:35:58 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231344AbiAZSf6 (ORCPT ); Wed, 26 Jan 2022 13:35:58 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60526 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230354AbiAZSf5 (ORCPT ); Wed, 26 Jan 2022 13:35:57 -0500 Received: from mxd1.seznam.cz (mxd1.seznam.cz [IPv6:2a02:598:a::78:210]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 5836EC061748; Wed, 26 Jan 2022 10:35:56 -0800 (PST) Received: from email.seznam.cz by email-smtpc26b.ko.seznam.cz (email-smtpc26b.ko.seznam.cz [10.53.18.37]) id 7c365e5627380a3f7d9f9208; Wed, 26 Jan 2022 19:35:36 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=seznam.cz; s=beta; t=1643222136; bh=N7Z0TgBqcMlNBuyZQo/fdQSFLPZ4eH8wQaILENj49WE=; h=Received:From:To:Cc:Subject:Date:Message-Id:X-Mailer:In-Reply-To: References:MIME-Version:Content-Transfer-Encoding:X-szn-frgn: X-szn-frgc; b=oPfbQv1uQOzyBqK55K7KpNxPIvo/vhjzoV6/KIeMdq2fozQKXB5Y3lXfxo58aprG+ prFjwa/iwTO9IbVAW10S83fdEaRTEKEUfLVIDg+nYyieU8WB9AN5FgmJnV3toL1O0H QuK4yC2dNl6o2nCsyGPs5O3ug+QVvB6wvwB+RN3Q= Received: from localhost.localdomain (ip-244-214.dynamic.ccinternet.cz [185.148.214.244]) by email-relay21.ko.seznam.cz (Seznam SMTPD 1.3.136) with ESMTP; Wed, 26 Jan 2022 19:35:27 +0100 (CET) From: michael.srba@seznam.cz To: Andy Gross , Bjorn Andersson , Rob Herring , Stephen Boyd , Philipp Zabel Cc: Linus Walleij , Florian Fainelli , Arnd Bergmann , Greg Kroah-Hartman , Saravana Kannan , linux-arm-msm@vger.kernel.org, linux-clk@vger.kernel.org, devicetree@vger.kernel.org, Michael Srba , Michael Srba Subject: [PATCH v4 5/5] arm64: dts: qcom: msm8998: reserve potentially inaccessible clocks Date: Wed, 26 Jan 2022 19:32:50 +0100 Message-Id: <20220126183250.11924-5-michael.srba@seznam.cz> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20220126183250.11924-1-michael.srba@seznam.cz> References: <20220126183250.11924-1-michael.srba@seznam.cz> MIME-Version: 1.0 X-szn-frgn: X-szn-frgc: <0> Precedence: bulk List-ID: X-Mailing-List: devicetree@vger.kernel.org From: Michael Srba With the gcc driver now being more complete and describing clocks which might not always be write-accessible to the OS, conservatively specify all such clocks as protected in the SoC dts. The board dts - or even user-supplied dts - can override this property to reflect the actual configuration. Signed-off-by: Michael Srba --- CHANGES: - v2: add this patch - v3: fix missing Signed-off-by - v4: add a proper explanation as per review, (hopefully) fix the subject and commit message --- arch/arm64/boot/dts/qcom/msm8998.dtsi | 15 +++++++++++++++ 1 file changed, 15 insertions(+) diff --git a/arch/arm64/boot/dts/qcom/msm8998.dtsi b/arch/arm64/boot/dts/qcom/msm8998.dtsi index f273bc1ff629..16dccf9d881e 100644 --- a/arch/arm64/boot/dts/qcom/msm8998.dtsi +++ b/arch/arm64/boot/dts/qcom/msm8998.dtsi @@ -863,6 +863,21 @@ gcc: clock-controller@100000 { clock-names = "xo", "sleep_clk"; clocks = <&xo>, <&sleep_clk>; + + /* + * The hypervisor typically configures the memory region where these clocks + * reside as read-only for the HLOS. If the HLOS tried to enable or disable + * these clocks on a device with such configuration (e.g. because they are + * enabled but unused during boot-up), the device will most likely decide + * to reboot. + * In light of that, we are conservative here and we list all such clocks + * as protected. The board dts (or a user-supplied dts) can override the + * list of protected clocks if it differs from the norm, and it is in fact + * desired for the HLOS to manage these clocks + */ + protected-clocks = , + , + ; }; rpm_msg_ram: sram@778000 {