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=-3.9 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS autolearn=no 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 3FD06C43461 for ; Tue, 8 Sep 2020 19:31:38 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 02C1320658 for ; Tue, 8 Sep 2020 19:31:37 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=alien8.de header.i=@alien8.de header.b="fJqbIq7w" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731458AbgIHTb3 (ORCPT ); Tue, 8 Sep 2020 15:31:29 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59314 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731130AbgIHTae (ORCPT ); Tue, 8 Sep 2020 15:30:34 -0400 Received: from mail.skyhub.de (mail.skyhub.de [IPv6:2a01:4f8:190:11c2::b:1457]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 1E892C0613ED for ; Tue, 8 Sep 2020 12:30:32 -0700 (PDT) Received: from zn.tnic (p200300ec2f10bf0059bdf9fa8e813382.dip0.t-ipconnect.de [IPv6:2003:ec:2f10:bf00:59bd:f9fa:8e81:3382]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.skyhub.de (SuperMail on ZX Spectrum 128k) with ESMTPSA id CCA7C1EC02B9; Tue, 8 Sep 2020 21:30:29 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=alien8.de; s=dkim; t=1599593429; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:in-reply-to:in-reply-to: references:references; bh=4Z3SaY9hLpwpb++kP8jU/6wRFeEbV6IvS5RvGnja5vE=; b=fJqbIq7w2ddlu/9gyzcdM/lrAC98pbJDH8w43vlzuiRzeH8tDGn+iS/Wwhpuem/QKtktet Lcp4IKgOPSiwcOymgS4CF5fkP1iz3n8CG25n1wPaW36aRz1xDTSneNF/+bMJk5GTjWYxlB 3+zMUho5DQXOn61YCkaVmRyYCemlHiQ= Date: Tue, 8 Sep 2020 21:30:29 +0200 From: Borislav Petkov To: Sultan Alsawaf Cc: "Jason A. Donenfeld" , Srinivas Pandruvada , kitsunyan , "Brown, Len" , X86 ML , LKML , Linus Torvalds Subject: Re: [PATCH] x86/msr: do not warn on writes to OC_MAILBOX Message-ID: <20200908193029.GM25236@zn.tnic> References: <20200907094843.1949-1-Jason@zx2c4.com> <20200907100647.GB10657@zn.tnic> <22617e57e541e460fac09db04fdb370f8e96e8ef.camel@linux.intel.com> <20200908172558.GG25236@zn.tnic> <20200908173656.GI25236@zn.tnic> <20200908180112.GK25236@zn.tnic> <20200908191838.GA2014@sultan-box.localdomain> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20200908191838.GA2014@sultan-box.localdomain> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Sep 08, 2020 at 12:18:38PM -0700, Sultan Alsawaf wrote: > I'd like to point out that on Intel's recent 14nm parts, undervolting > is not so much for squeezing every last drop of performance out of the > SoC as it is for necessity. Sounds to me that this undervolting functionality should be part of the kernel and happen automatically. I have no clue, though, whether people who do it, just get lucky and undervolting doesn't cause any other hardware issues, or there's a real reason for this power madness and if not done, power-related failures happen only on some boxes so they decided to do them on all. Or maybe BIOS is nuts, which is not a stretch. Srinivas, what's the story here? -- Regards/Gruss, Boris. https://people.kernel.org/tglx/notes-about-netiquette