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 DDAFEC4320A for ; Tue, 24 Aug 2021 17:16:16 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C60B3610FD for ; Tue, 24 Aug 2021 17:16:16 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S240206AbhHXRQ7 (ORCPT ); Tue, 24 Aug 2021 13:16:59 -0400 Received: from mail.kernel.org ([198.145.29.99]:52016 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S239439AbhHXROB (ORCPT ); Tue, 24 Aug 2021 13:14:01 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 28BD561A7B; Tue, 24 Aug 2021 17:01:33 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1629824493; bh=sRcdw/m1r+YBgbtvwqRQ1X9Gu951mClHv48QPe5NpBc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=WakqbpanwIcPwhmr0PQt+X2fLLDCU7WhPBjBuDcCO1ZwP5/PsW7wsGMhH5UeeGyZb lbyVwgjXXjfRpZVU9IRuzzIFmMNVhtFiH3x4x3KEpcB+J3bEP9yHW0OgVRlPswjQ1u DYTaTOwSEGiVqtosenx0fz0/X1rPMB1lgXLHSWEhDize0pYkJKR0forGfAwdyOEAmb aoWbGW7eNa6FBYXViXkFv0iflxYwZhJOvj/dlfZc7phhYJzesL35ixn6S6XLc1XhK3 4F5JIoDrDeNkLqRC6/arbflA/CBTjfnBXADHSERX0hcgbn/O7iXE0ar8OyCpV9+Xmi aa7Dkib9H+rSQ== 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 5.4 26/61] cpufreq: armada-37xx: forbid cpufreq for 1.2 GHz variant Date: Tue, 24 Aug 2021 13:00:31 -0400 Message-Id: <20210824170106.710221-27-sashal@kernel.org> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20210824170106.710221-1-sashal@kernel.org> References: <20210824170106.710221-1-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-5.4.143-rc1.gz X-KernelTest-Tree: git://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable-rc.git X-KernelTest-Branch: linux-5.4.y X-KernelTest-Patches: git://git.kernel.org/pub/scm/linux/kernel/git/stable/stable-queue.git X-KernelTest-Version: 5.4.143-rc1 X-KernelTest-Deadline: 2021-08-26T17:01+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 e4782f562e7a..2de7fd18f66a 100644 --- a/drivers/cpufreq/armada-37xx-cpufreq.c +++ b/drivers/cpufreq/armada-37xx-cpufreq.c @@ -102,7 +102,11 @@ 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