From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-19.7 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id D315EC4320E for ; Tue, 24 Aug 2021 16:57:59 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id BE79E617E3 for ; Tue, 24 Aug 2021 16:57:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238674AbhHXQ6m (ORCPT ); Tue, 24 Aug 2021 12:58:42 -0400 Received: from mail.kernel.org ([198.145.29.99]:39584 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234861AbhHXQ53 (ORCPT ); Tue, 24 Aug 2021 12:57:29 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 2738961409; Tue, 24 Aug 2021 16:56:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1629824204; bh=04o+o1gg3m8SgoYqbhihayaGyn+eXrwxHYNUCwfx2eY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=kHHIWLBEr2t8fmmdOrW4Ag7PT1xTlLV323oKujvPMHCH4Kfm801mWU9UB7umCwOwm mHLc7/HByNJXSTHXZ0VL97v7IbmAivwNcqB1THpQyaEbLNFkM22OnNf/NoDe5+2ltm CVWhHf/HiUkf6V7H5Cc+yT9EKX+lkofbHHc5GBYoh3rC3vkyqCvRCdlI/Yah3iv6jy MywY4JidxiUsF7rt9DMazIaw3cYdpk0dACtVoeHpIWrqFM18kkYEcJmw1aD3cbT3n2 Z231bTXfU5crrD5Wv09bKb2LQ6bmgSTL9fRdQkPBxpjAmPp2aVHjB8yckUaSWRj4MH MbGZQ8WCGiWuA== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: =?UTF-8?q?Marek=20Beh=C3=BAn?= , Viresh Kumar , Sasha Levin Subject: [PATCH 5.13 037/127] cpufreq: armada-37xx: forbid cpufreq for 1.2 GHz variant Date: Tue, 24 Aug 2021 12:54:37 -0400 Message-Id: <20210824165607.709387-38-sashal@kernel.org> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20210824165607.709387-1-sashal@kernel.org> References: <20210824165607.709387-1-sashal@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 X-KernelTest-Patch: http://kernel.org/pub/linux/kernel/v5.x/stable-review/patch-5.13.13-rc1.gz X-KernelTest-Tree: git://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable-rc.git X-KernelTest-Branch: linux-5.13.y X-KernelTest-Patches: git://git.kernel.org/pub/scm/linux/kernel/git/stable/stable-queue.git X-KernelTest-Version: 5.13.13-rc1 X-KernelTest-Deadline: 2021-08-26T16:55+00:00 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Marek Behún [ Upstream commit 484f2b7c61b9ae58cc00c5127bcbcd9177af8dfe ] The 1.2 GHz variant of the Armada 3720 SOC is unstable with DVFS: when the SOC boots, the WTMI firmware sets clocks and AVS values that work correctly with 1.2 GHz CPU frequency, but random crashes occur once cpufreq driver starts scaling. We do not know currently what is the reason: - it may be that the voltage value for L0 for 1.2 GHz variant provided by the vendor in the OTP is simply incorrect when scaling is used, - it may be that some delay is needed somewhere, - it may be something else. The most sane solution now seems to be to simply forbid the cpufreq driver on 1.2 GHz variant. Signed-off-by: Marek Behún Fixes: 92ce45fb875d ("cpufreq: Add DVFS support for Armada 37xx") Signed-off-by: Viresh Kumar Signed-off-by: Sasha Levin --- drivers/cpufreq/armada-37xx-cpufreq.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/drivers/cpufreq/armada-37xx-cpufreq.c b/drivers/cpufreq/armada-37xx-cpufreq.c index 3fc98a3ffd91..c10fc33b29b1 100644 --- a/drivers/cpufreq/armada-37xx-cpufreq.c +++ b/drivers/cpufreq/armada-37xx-cpufreq.c @@ -104,7 +104,11 @@ struct armada_37xx_dvfs { }; static struct armada_37xx_dvfs armada_37xx_dvfs[] = { - {.cpu_freq_max = 1200*1000*1000, .divider = {1, 2, 4, 6} }, + /* + * The cpufreq scaling for 1.2 GHz variant of the SOC is currently + * unstable because we do not know how to configure it properly. + */ + /* {.cpu_freq_max = 1200*1000*1000, .divider = {1, 2, 4, 6} }, */ {.cpu_freq_max = 1000*1000*1000, .divider = {1, 2, 4, 5} }, {.cpu_freq_max = 800*1000*1000, .divider = {1, 2, 3, 4} }, {.cpu_freq_max = 600*1000*1000, .divider = {2, 4, 5, 6} }, -- 2.30.2